What is an astronomical unit? | Space | EarthSky What is an astronomical unit? By Bruce McClure in Space | October 21, 2016 Astronomers use astronomical units – or AU – to describe solar system distances. Definition of AU here. Also, mean distances in AU to prominent solar system objects. Artist’s concept of Earth and sun. One astronomical unit = the average distance between them. Image via NASA . 2017 EarthSky Lunar Calendar pre-sale…is happening NOW! Astronomers like to list the distances to objects within our solar system (planets, dwarf planets, asteroids, comets, spacecraft, etc.) in terms of an astronomical unit. How far is that? Follow the links below to learn more about this basic distance unit in our solar system. Definition of astronomical unit. For general reference, we can say that one astronomical unit (AU) represents the mean distance between the Earth and our sun. An AU is approximately 93 million miles (150 million km). It’s approximately 8 light-minutes. More exactly, one astronomical unit (AU) = 92,955,807 miles (149,597,871 km).

Earth’s orbit around the sun isn’t a perfect circle. So Earth’s distance from the sun changes throughout the year. Astronomers give the Earth’s changing distance throughout the year relative to the astronomical unit, too. For instance, when the Earth is at perihelion – its nearest point to the sun for the year, in January – it’s about 0.983 AU from the sun. When our planet swings out to aphelion – its farthest point, in July – we’re about 1.017 AU away from the sun. Distances from the sun of planets in our solar system, expressed in A.U. Graph via planetsforkids.org Mean distance ( semi-major axis ) from sun to each planet, in AU. Mercury: 0.387 AU Source: Planetary Fact Sheet If you want to find out the distances of the solar system planets from the Earth and sun right now, click here or here . Artist’s concept of the dwarf planet Eris, whose distance from the sun varies from 38.255 to 97.661 au. Image via HubbleSite Mean distance from sun to some dwarf planets, in AU.

Ceres: 2.767 AU Eris: 67.958 AU Sedna: 518.57 AU Artist’s rendering of the Kuiper Belt and the Oort Cloud, the distant icy realm of the solar system. Image via NASA Mean distance to Kuiper Belt, farthest spacecraft, Oort Cloud, in AU. Oort Cloud : 5,000 to 100,000 AU Largest circle with yellow arrow indicates one light year from our sun. Smallest yellow sphere is one light-week. Larger yellow sphere is one light-month. Read more about this image at Wikimedia Commons. Amount of distance in a light-year, in AU One light-year = 63,240 AU Bottom line: Astronomers like to list the distances to objects within our solar system (planets, dwarf planets, asteroids, comets, spacecraft, etc.) in terms of the astronomical unit, or AU. One astronomical unit is the approximate mean distance between the Earth and sun. It’s about 93 million miles (150 million km), or 8 light-minutes.

Glossary: Astronomical Unit (AU) ASTRONOMICAL UNIT (AU) 1 AU = 149,597,870.700 kilometers (or 149,597,870,700 meters) Definition: An Astronomical Unit is the mean distance between the Earth and the Sun. In 2012, the International Astronomical Union defined the distance to be 149,597,870,700 meters. Historical Background: Tycho Brahe estimated the distance between the Sun and the Earth at 8 million kilometers (5 million miles). Later, Johannes Kepler estimated the AU was at 24 million kilometers (15 million miles). In 1672, Giovanni Cassini made a much better estimate by using Mars. By observing Mars from Paris and having a colleague, Jean Richer, also observe Mars at the same time in French Guiana in South America, Cassini was able to determine the parallax of Mars. From that Cassini was then able to calculate the distance from Earth to Mars, and then the distance from Earth to the Sun.

Cassini calculated the AU to be at 140 million kilometers (87 million miles), which is lower, but very close to the modern day number. Sun Facts 1. The SUN is just ONE of about 100 billion STARS in our GALAXY. 2. It has a DIAMETER of 1,390,000 km 3. Its CORE temperature is 15 million º C. 4. Its SURFACE temperature is 5,500 ºC. Cooler (3,800 ºC) surface areas are called SUN SPOTS. 5. It is the LARGEST object in the SOLAR SYSTEM and makes up 99.8% of the total MASS of the Solar System. 6. It consists of 75% HYDROGEN and 25% HELIUM. 7. The ENERGY output of the Sun is about 386 billion megawatts and is produced by NUCLEAR FUSION, using Hydrogen as fuel. 8. Apart from HEAT and LIGHT, the Sun also emits a stream of CHARGED PARTICLES called the SOLAR WIND. The Solar Wind:- a.

- Causes Radio INTERFERENCE at certain times b. - Produces the AURORA BOREALIS or "The NORTHERN LIGHTS" c. - Causes the characteristic TAILS of COMETS. d. - Alters the TRAJECTORY of SPACECRAFT 9. The Sun is about 4.5 BILLION YEARS old. It will probably continue to exist in its present FORM for about another 5 BILLION YEARS before RUNNING out of HYDROGEN. 10. There are NINE planets orbiting the SUN (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto) QUESTIONS ON THE SUN 1. Why do Sun Spots appear to be DARK in colour? 2. The average POWER PRODUCTION of all the Power Stations in the USA is about 320,000 megawatts. How many MORE times POWER does the Sun GENERATE than this? 3. How LONG does LIGHT take to travel from the Sun to the Earth? (the Earth is 150 million km from the Sun and light travels at 300,000 km per second). 4.

Why must the SOLAR WIND be taken into account when planning SPACE MISSIONS? 5. Is the Sun a SOLID body like the Earth? Explain your answer. How Far Are The Planets From The Sun? - Universe Today Universe Today How Far Are The Planets From The Sun? Article Updated: 26 Jul , 2016 by Elizabeth Howell The eight planets in our solar system each occupy their own orbits around the Sun. They orbit the star in ellipses, which means their distance to the sun varies depending on where they are in their orbits. When they get closest to the Sun, it’s called perihelion, and when it’s farthest away, it’s called aphelion. So to talk about how far the planets are from the sun is a difficult question, not only because their distances constantly change, but also because the spans are so immense — making it hard for a human to grasp. For this reason, astronomers often use a term called astronomical unit , representing the distance from the Earth to the Sun.

The table below (first created by Universe Today founder Fraser Cain in 2008) shows all the planets and their distance to the Sun, as well as how close these planets get to Earth. Mercury: Closest: 46 million km / 29 million miles (.307 AU) Farthest: 70 million km / 43 million miles (.466 AU) Average: 57 million km / 35 million miles (.387 AU) Closest to Mercury from Earth: 77.3 million km / 48 million miles Venus: Closest: 107 million km / 66 million miles (.718 AU) Farthest: 109 million km / 68 million miles (.728 AU) Average: 108 million km / 67 million miles (.722 AU) Closest to Venus from Earth: 40 million km / 25 million miles The planet Venus, as imaged by the Magellan 10 mission.

Credit: NASA/JPL Earth: Closest: 147 million km / 91 million miles (.98 AU) Farthest: 152 million km / 94 million miles (1.01 AU) Average: 150 million km / 93 million miles (1 AU) Mars: Closest: 205 million km / 127 million miles (1.38 AU) Farthest: 249 million km / 155 million miles (1.66 AU) Average: 228 million km / 142 million miles (1.52 AU) Closest to Mars from Earth: 55 million km / 34 million miles Jupiter: Closest: 741 million km /460 million miles (4.95 AU) Farthest: 817 million km / 508 million miles (5.46 AU) Average: 779 million km / 484 million miles (5.20 AU) Closest to Jupiter from Earth: 588 million km / 346 million miles Artist’s impression of Jupiter and Io.

Credit: NASA/JPL Saturn: Closest: 1.35 billion km / 839 million miles (9.05 AU) Farthest: 1.51 billion km / 938 million miles (10.12 AU) Average: 1.43 billion km / 889 million miles (9.58 AU) Closest to Saturn from Earth: 1.2 billion km /746 million miles Uranus: Closest: 2.75 billion km / 1.71 billion miles (18.4 AU) Farthest: 3.00 billion km / 1.86 billion miles (20.1 AU) Average: 2.88 billion km / 1.79 billion miles (19.2 AU) Closest to Uranus from Earth: 2.57 billion km / 1.6 billion miles Neptune: Closest: 4.45 billion km /2.77 billion miles (29.8 AU) Farthest: 4.55 billion km / 2.83 billion miles (30.4 AU) Average: 4.50 billion

 km / 2.8 billion miles (30.1 AU) Closest to Neptune from Earth: 4.3 billion km / 2.7 billion miles As a special bonus, we’ll include Pluto too, even though Pluto is not a planet anymore.

Uranus and Neptune, the Solar System’s ice giant planets. Credit: Wikipedia Commons Pluto: Closest: 4.44 billion km / 2.76 billion miles (29.7 AU) Farthest: 7.38 billion km / 4.59 billion miles (49.3 AU) Average: 5.91 billion km / 3.67 billion miles (39.5 AU) Closest to Pluto from Earth: 4.28 billion km / 2.66 billion miles To learn more: How far away is the Sun? | Cool Cosmos How far away is the Sun? The Sun is at an average distance of about 93,000,000 miles (150 million kilometers) away from Earth. It is so far away that light from the Sun, traveling at a speed of 186,000 miles (300,000 kilometers) per second, takes about 8 minutes to reach us. Like all of the other planets in our Solar System, Earth does not travel around the Sun in a perfect circle.

Instead its orbit is elliptical, like a stretched circle, with the Sun just off the center of the orbit. This means that the distance between Earth and the Sun changes during a year. At its closest, the Sun is 91.4 million miles (147.1 million km) away from us. At its farthest, the Sun is 94.5 million miles (152.1 million km) away. The Earth is closest to the Sun during winter in the northern hemisphere. Continue the conversation on Sun Facts ☀️ - Interesting Facts about the Sun - Space Facts Sun size compared to Earth, Neptune, Uranus, Saturn and Jupiter Facts about the Sun At its centre the Sun reaches temperatures of 15 million °C. The Sun is all the colours mixed together, this appears white to our eyes. The Sun is mostly composed of hydrogen (70%) and Helium (28%). The Sun is a main-sequence G2V star (or Yellow Dwarf). The Sun is 4.6 billion years old. The Sun is 109 times wider than the Earth and 330,000 times as massive. Detailed Sun Facts One million Earths could fit inside the Sun.

If a hollow Sun was filled up with spherical Earths then around 960,000 would fit inside. On the other hand if these Earths were squished inside with no wasted space then around 1,300,000 would fit inside. The Sun’s surface area is 11,990 times that of the Earth’s. The Sun contains 99.86% of the mass in the Solar System. The mass of the Sun is approximately 330,000 times greater than that of Earth. It is almost three quarters Hydrogen, whilst most of the remaining mass is Helium. The Sun is an almost perfect sphere. There is only a 10 kilometre difference in its polar diameter compared to its equatorial diameter. Considering the vast expanse of the Sun, this means it is the closest thing to a perfect sphere that has been observed in nature. The temperature inside the Sun can reach 15 million degrees Celsius. At the Sun’s core, energy is generated by nuclear fusion, as Hydrogen converts to Helium. Because hot objects generally expand, the Sun would explode like a giant bomb if it weren’t for its enormous gravitational force.

The temperature on the surface of the Sun is closer to 5,600 degrees Celsius. Eventually, the Sun will consume the Earth. When all the Hydrogen has been burned, the Sun will continue for about 130 million more years, burning Helium, during which time it will expand to the point that it will engulf Mercury and Venus and the Earth. At this stage it will have become a red giant The Sun will one day be about the size of Earth. After its red giant phase, the Sun will collapse, retaining its enormous mass, but containing the approximate volume of our planet. When this happens, it will be called a white dwarf. Light from the Sun takes eight minutes to reach Earth. With a mean average distance of 150 million kilometres from Earth and with light travelling at 300,000 kilometres per second, dividing one by the other gives us an approximate time of 500 seconds, or eight minutes and 20 seconds. Although this energy reaches Earth in a few minutes, it will already have taken millions of years to travel from the Sun’s core to its surface. The Sun travels at 220 kilometres per second.

The Sun is 24,000-26,000 light years from the galactic centre and it takes the Sun 225-250 million years to complete an orbit of the centre of the Milky Way . The distance from the Sun to Earth changes throughout the year. Because the Earth travels on an elliptical orbit around the Sun, the distance between the two bodies varies from 147 to 152 million kilometres. The distance between the Earth and the Sun is called an Astronomical Unit (AU). The Sun is middle-aged. At around 4.5 billion years old, the Sun has already burned off about half of its store of Hydrogen. It has enough left to continue to burn Hydrogen for approximately another 5 billion years. The Sun is currently a type of star known as a Yellow Dwarf The Sun has a very strong magnetic field. Solar flares occur when magnetic energy is released by the Sun during magnetic storms, which we see as sunspots. In sunspots, the magnetic lines are twisted and they spin, much like a tornado would on Earth. The Sun generates solar wind.

This is a stream of charged particles, which travels through the Solar System at approximately 450 kilometres per second. Solar wind occurs where the magnetic field of the Sun extends into space instead of following its surface. Satellites Earth Makes Closest Approach to Sun of the Year Earth Makes Closest Approach to Sun of the Year By SPACE.com Staff | January 5, 2012 07:01am ET MORE If the sun appears a bit more intense than normal to you this week, you're not seeing things. The Earth has just made its closest approach to our nearest star for the year. The orbital milestone is known as " perihelion ," and it marks the time when the distance between the Earth and the sun is at its smallest. The event occurs every year in early January, and in 2012 it took place Wednesday, Jan. 4 at 8 p.m. EST (or Jan. 5 at 0100 GMT, depending on your time zone). On average, the Earth orbits the sun at a distance of about 93 million miles (150 million kilometers).

This distance is known as 1 astronomical unit (AU), and it serves as a yardstick for distances to other planets in our solar system. Mars, for example, is about 1.5 AU from the sun, while Jupiter is about 5.2 AU from the star. But like the other planets in our solar system, the Earth's orbit is not a perfect circle . Instead, it is slightly elliptical — or oval-shaped — meaning it has a closest point to the sun (perihelion) and a farthest point (which is known as aphelion). During the 2012 perihelion, the Earth was about 91.3 million miles (147 million km) from the sun, or about 0.983 AU. The Earth will reach aphelion on July 5. At that time, our planet will be about 94.5 million miles (152 million km) — or 1.017 AU — from the sun. The difference between the two extremes of Earth's orbit is just over 3 million miles (5 million km).

In January, the sun can appear to shine about 7 percent more intensely than it does in July during aphelion, according to NASA descriptions. [ Top 10 Views of Earth from Space ] This image shows a comparison of HMI Quick-Look continuum images from January 2012 (right) and July 2011 as seen by NASA's Solar Dynamics Observatory. The two horizontal lines show how high the sun appears today. When those lines are extended to the left, the July image is a little over 3 percent smaller. Credit: NASA/SDO If you live in the Northern Hemisphere, the fact that Earth is closest to the sun during the cold winter season may be confusing, but there is an explanation. The Earth's changing seasons are actually determined by our planet's tilt on its axis, not its distance from the sun. Our planet spins on an axis that is tilted about 23.5 degrees from vertical. This tilts the Northern Hemisphere away from the sun during the northern winter and toward the sun during the northern summer. The Earth's closest approach to the sun each year has effects that can reach all the way into space.

Several space telescopes keep constant watch on the sun to study its solar storm and flare activity. Since some of those probes are stationed near Earth or its orbit, scientists had to take into account the variations in the sun's apparent size when the planet reaches its perihelion and aphelion. One of those spacecraft is NASA's Solar Dynamics Observatory (SDO), which has several cameras to record high-definition videos of the sun . SDO mission scientists said Earth's perihelion played a big role in choosing the spacecraft's digital cameras (known as charged coupled devices, or CCDs). "Why do we care? Because SDO takes a lot of pictures of the sun. At perihelion they appear a little bigger than they do at aphelion in July," mission scientists explained in a blog post. "When we designed the instruments on SDO we had to make sure the largest appearance of the sun would fit on the CCDs." Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook . Planetary Size and Distance Comparison - National Geographic Society Planetary Size and Distance Comparison What is the diameter and relative distance from the sun of each planet in our solar system?

This lists the logos of programs or partners of NG Education which have provided or contributed the content on this page. Program Tips & Modifications Modification If you do not have enough space to do the kinesthetic model, you can modify this activity to have students create a string-and-bead solar system model in the classroom by converting astronomical units to a 10 centimeter/AU (4 inch) scale. Students will need a string 4.5 meters long. Have students tie beads in place to represent planetary distances. Sun 0.0 AU=0 cm Mercury 0.4 AU=4 cm Venus 0.7 AU=7 cm Earth 1.0 AU=10 cm Mars 1.5 AU=15 cm Asteroid Belt 2.8 AU=28 cm Jupiter 5.2 AU=52 cm Saturn 9.6 AU=96 cm Uranus 19.2 AU=192 cm Neptune 30.0 AU=300 cm Tip Make sure students understand that these are only models or visualizations of the relative distances between the planets and the sun. Planets all orbit the sun at different velocities, so they rarely form a straight line from the sun.

Instead, they appear somewhere along their orbital paths. 1. Review planet order and relative sizes in our solar system . Display the NASA illustration: All Planet Sizes. Ask students to point out the location of Earth. Then challenge them to identify all of the planets, outward from the sun (left to right): inner planets Mercury, Venus, Earth, Mars; outer planets Jupiter, Saturn, Uranus, Neptune, and Pluto. Remind students that Pluto is no longer considered a planet in our solar system; it was downgraded to the status of dwarf planet in 2006. Point out the locations of the asteroid belt (between Mars and Jupiter) and Kuiper belt (past Pluto) if they were included in this illustration. Explain to students that the illustration shows the planets in relative size . Ask: What do you think relative size means? Elicit from students that the pictures show how big the planets are when compared to each other and to the sun. Ask: Which planet is the smallest? (Mercury) Which is the largest? (Jupiter) 2. Have students gather data and compare planet sizes. Divide students into small groups. Distribute one copy of the worksheet Planetary Size Comparison to each group.

Have groups use the Planet Size Comparison interactive to find and record data on planet diameters and ratios. Ask: What do you notice about the size of the planets? (Possible response: The inner, rocky planets are smaller than the outer, gaseous planets.) How do you think the sizes of the planets compare? (Possible response: There is a big difference in the sizes of the planets. Some are fairly small and others are extremely large.) Would it be easy to model the planet sizes? Why or why not? (Possible response: No, because of the great differences in size.) How could we model differences? What everyday objects could represent planets and the sun? (Possible responses: peas/beach ball; grains of sand/orange) Have students discuss the answers in their small groups. Then regroup as a class to discuss students’ ideas. 3. Build background about the astronomical unit (AU). Explain to students that an astronomical unit, or AU, is a simplified number used to describe a planet’s distance from the sun. It is a unit of length equal to the average distance from Earth to sun, approximately 149,600,000 kilometers (92,957,000 miles).

Only Earth can be assigned AU 1. Planets farther away would have AU greater than 1; planets closer would have AU less than 1. Ask: Why do you think scientists find it helpful to use astronomical units? (Possible response: Distances in the solar system are very large. Using AU helps keep the numbers manageable, or smaller, so we can easily calculate very large distances.) What are the challenges of using kilometers or miles instead? (Possible response: Using kilometers or miles would make calculations more difficult and could produce errors in measurements required to accurately send a probe or lander to another planet.) Explain to students that the astronomical unit provides a way to express and relate distances of objects in the solar system and to carry out astronomical calculations. For example, stating that the planet Jupiter is 5.2 AU (5.2 Earth distances) from the sun and that Pluto is nearly 40 AU allows you to more easily compare the distances of all three bodies. 4. Introduce the modeling activity. Tell students that they are going to stand in for the planets and planetary objects in order to create a model of relative planetary sizes and relative distance s. Display the NASA illustration: How Big is the Sun?

to give students a sense of the relative sizes of planets compared to an everyday object like a basketball. Make sure students understand that the distances between the planets are very large compared to the sizes of each planet. This makes it extremely difficult to create an exact scale of our solar system, so this activity will focus on the distance comparison. 5. Have groups create models of relative planetary distances. Divide students into groups of 9, 10 or 11, depending on class size. (If 9, one student represents the sun and the remaining students represent 8 planets; If 10, the sun, planets, and asteroid belt; If 11, the sun, planets, asteroid belt, and Kuiper Belts) Take students to a large area, such as the gymnasium or empty parking lot.

You’ll need enough space for each group to spread out and create their model, using the following scale, with each step equaling approximately 1 meter (about 3.28 feet): Sun: stands at the edge of the area Mercury = 1 step from sun Venus = 2 steps from sun Earth = 2.5 steps from sun Mars = 4 steps from sun Asteroid belt = 8 steps from sun Jupiter = 13 steps from sun Saturn = 24 steps from sun Uranus = 49 steps from sun Neptune = 76 steps from sun Kuiper belt = 100 steps from sun Emphasize that at this scale, the sun would be less than 1.3 centimeters (0.5 inches) in diameter . Ask students to describe what they notice about planetary distances from the model. If needed, allow one student from each group to put an object in their place and walk around their group’s model to make observations. 6. Have students make a math connection. Distribute copies of the worksheet Stepping Out the Solar System to each group. Have students recalculate the number of paces for each planet’s orbit, as constrained by the size of the available area.

Use the provided answer key to check groups’ work. Then have students recreate the model. Informal Assessment Have students work independently to summarize, in writing, what they learned about our solar system, including: locations of planets in relation to the sun and one another relative sizes of planets, including Earth relative distances of planets any conclusions they can draw about the locations of the asteroid belt and Kuiper belt Extending the Learning Encourage students to practice backyard astronomy. At certain times of day and year, it's possible to view planets Mercury, Venus, Mars, Jupiter, and Saturn with the naked eye. Students can use Sky and Telescope Magazine's Sky at a Glance feature to find out what planets are visible in the night sky and where to look. Ask students to report back to the class with what they observed. Subjects & Disciplines User Permissions For information on user permissions, please read our Terms of Service . If you have questions about licensing content on this page, please contact natgeocreative@ngs.org for more information and to obtain a license. If you have questions about how to cite anything on our website in your project or classroom presentation, please visit our FAQ page .

Media Some media assets (videos, photos, audio recordings and PDFs) can be downloaded and used outside the National Geographic website according to the Terms of Service . If a media asset is downloadable, a download button appears in the lower right hand corner ( ) of the media viewer. If no button appears, you cannot download or save the media. Text Text on this page is printable and can be used according to our Terms of Service . Interactives Any interactives on this page can only be played while you are visiting our website. You cannot download interactives. Windows to the Universe February 21, 2011 Daniel(United States) I know the tilt of the earth causes earth's seasons. Regardless of that, what was the exact distance of the earth from the sun in June and December of 2010? The distance D of the earth from the sun is always slowly swinging between its minimum and maximum values. D is minimum (about 147,098,070 kilometers) at "perihelion" around January 3, and D is maximum (about 152,097,700 kilometers) at "aphelion" around July 3.

See the article Perihelion and Aphelion . May 10, 2010 Clifton (Louisiana/USA) What is the speed of the earth as it rotates on its axis? Our planet completes one full rotation in 24 hours. Considering that the circumference of the earth at the equator is 24,901.55 miles (about 40 075 kilometers), a spot on the equator rotates at approximately 1037.5646 miles per hour or 1669.8 km/h. March 3, 2010 What is the exact approximation of earths orbit speed around the sun? Thank you. Earth's average orbital speed is 107 218 km/h (66622 mph). January 13, 2010 Vinny What force makes the Earth rock and roll on its axis? Let's look at a particular motion of Earth's axis, the precession or axial rotation (Earth wobbles on it axis as it spins, completing a full wobble every 23 000 years). This was explained by Newtonian physics.

Earth has a nonspherical shape, bulging outward at the equator. The gravitational tidal forces of the Moon and Sun apply torque as they attempt to pull the equatorial bulge into the plane of the ecliptic. January 11, 2010 rachael (ohio) I you were in a space ship looking down at the earth would you see the earth rotate? Absolutely! It will complete a full rotation in 24 hours! October 19, 2009 Monica (Ohio) How do we know earth rotates west to east? One of the most important clue is that the Sun rises from the east and sets on the west. October 2, 2009 mabidka (Pakistan) what is the direction of earth rotationi i.e north, south, east, west? The Earth rotates towards the east. As viewed from the North Star Polaris, the Earth turns counter-clockwise. September 30, 2009 t (England) Because the Earth gains an extra day every four years. Does this mean it gains an extra week every seventh leap year.

Because a year in our planet is not an exact multiple of 24-hour days, the leap years account for the resultant difference. It is not that a new day is added every 4 years, or a week every 7 leap years, we are just "compensating" for the difference. September 25, 2009 Jacqueline (philippines) why we can't feel the earth is moving? Because we are so small and moving on its surface along it, that we can't easily see the motion. But the day-night cycle, the seasons, the apparent motion of the stars, etc. are clear indication of the Earth motion. September 25, 2009 AUGUSTINE (KERALA/INDIA) Why is earth's orbit around sun elliptical? Due to the fact that all gravitational interactions with other objects in the solar system can disrupt a perfectly circular orbit, elliptical orbits are the norm (circular orbits are rare). However, the Earth's orbit, with an eccentricity of only 0.02, is very circular. August 19, 2009 darren (australia) does the earth move off its orbit around the sun at all, even slightly?

Your question is not clear. Orbit, in a very simple definition, is the path that a planet follows around the Sun. There are simple aproximations (circular orbits), no so simple (elliptical orbits) and very complex ones to describe the motion of a planet around the star. See, for example, this page for some motions of our planet, and this one for background information. April 16, 2009 sirana (queensland, austlia) we do we have night time and day time sir????? and why do we call it that sir??? i love the night time because i see the stars very bright were i live. why is that sir??? The succesion of days and nights are due to the rotation of the earth around its own axis. This happens because the side that our planet shows to the Sun is always changing due to this rotation. April 13, 2009 Ana (Germany) "What force makes earth to spin around its axis, but around the Sun?" The rotation of the Earth, and other planets, about their axis is a remanent of the rotation of the planetary nebula from where all were formed.

March 4, 2009 Jenna (united states) Explain the rotation of the earthon its axis and its connection to our day and night. The Earth rotates around once in 24 hours. The time it takes for the Earth to rotate completely around once is what we call a day. It's Earth's rotation that gives us night and day. MOre information on our web page The Earth's Rotation . February 24, 2009 jim (pa usa) how many miles a day does the earth travel (move) from december 21 to march 21(91 diferent answers) from north to south is 1616 miles The differences could be related with the different assumptions made. For example, using an average distance Sun-Earth of 150 million kilometers (93.2 million miles), we can obtain the lenght of the circunference multiplying by 2 Pi, which gives 585.6 million miles for the circumference. Dividing this by 365.25 days/year gives 1.603 million miles per day (in average, since the orbit is silghtly elliptical).

February 24, 2009 Alan (michigan) How do the earth rotate? The Earth rotates towards the east. As viewed from the North Star Polaris, the Earth turns counter-clockwise. February 18, 2009 kiryn (usa) how fast does earth rotate? The speed at which the earth spins varies upon your latitudinal location on the planet. Athe equator, where the circumference of the Earth is greatest, the speed is about 1 670 km/h, or 1 038 miles per hour January 22, 2009 meyar (uae) how are days sometimes long sometimes short? It depends on the season and latitude you are at. For low latitudes, near the equator, the lnght of the day will stay roughly the same along the year. For a background information see our web page Earth's Tilt Is the Reason for the Seasons! . Winter (for the Northern Hemisphere!) is represented by the top figure of this page.

There you can see that due to the Earth's tilt, a wider area of our planet is on the dark side, corresponding to the well known fact of longer nights and shorter days for this season. October 1, 2008 yagaira (usa) what is the position of the earth during the summer solstice? The summer solstice occurs when the tilt of the Earth's axis is most oriented toward the Sun, causing the Sun to reach its northernmost (North Hemisphere) and southernmost (South Hemisphere) extremes. More information can be found on our web page The Summer Solstice . September 26, 2008 Waleed (the UK) As far as I know, the Earth is accelerating when it is approching the Sun i.e passing the Periheilon. Why we do not feel the accelration? Why no Tsunamy happens every time the Earth changes its speed.. Our planet orbit has an eccentricity of 0.017, which means our orbit is very close to a circular shape. Therefore the assumed change of speed, which on top of this happens over a considerable amount of time (making the value of the acceleration very low) is not really significant.

September 25, 2008 Julia (New Mexico, USA) Does the earth move at a constant velocity about the sun, throughout the year? I heard that it speeds up when it is closer to the sun. Is this just an apparent increase in speed like if you are at a race track and the cars seem faster when they are going right past you, or does gravity have a slingshot effect? No, Earth's (and any other planet's) speed changes with the distance to the Sun. This is clearly captured by Kepler's laws, specifically Kepler's equal-area law: The line connecting a planet to the sun sweeps out equal areas in equal amounts of time. July 8, 2008 michael (Phoenix, AZ) Can you explain to me each of the three major movements of the Earth, as well as the effect of the Earth's tilted axis Earth has two important movements. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year.

The third movement is related with Earyh's axis. Earth's rotation axis is not fixed in space, its direction executes a slow precession with a period of 26,000 years. July 7, 2008 RAVEN (usa) What is the vernal equinox? Seasons are related with the tilt of Earth axis. The dates of maximum tilt correspond to summer and winter solstice, and the dates of zero tilt to the vernal (spring) and autumnal equinoxes. June 27, 2008 What causes stars to appear to follow circular paths in the night sky? That the stars appear to follow daily circular paths around Polaris is the best supporting evidence that the Earth rotates on its axis. April 2, 2008 Rosa (WA. USA) Is there a third movement of the earth around the sun? There is one that ocurres evry 24 hrs. and the other every 365 1/4 days, but what about the tilting away and towards the Sun at the same time?

The Earth's rotation axis is not fixed in space, its direction executes a slow precession with a period of 26,000 years. See this page for more information. March 19, 2008 Per (Sweden) The eccentricity of Earth's orbit changes due to interaction from the other planets, but the major axis remains the same (I have heard). How comes? A significant change in eccentricity will result in a change of the semi-major axis. This animation , developed by Randy M. Russell, part of the Windows to the Universe team, will give you a clear visualization of these changes. March 18, 2008 Courtney (mass) How fast is the Earth moving? The Earth completes a full orbit (approximately 940 million km) around the sun in about 365 days (a year). Considering that each day has 24 hrs, it follows that the translational speed of our planet around the Sun is about 107 305.9 km/h or 1 788 432.2 m/s. March 11, 2008 How does the sun orbit the earth?

All planets, including Earth, orbit the Sun following an elliptical path. January 12, 2008 christopher ( US Michigan) In which direction does the earth spin? As seen from the North Pole, our planet spins in a counterclockwise direction (and also travels around the sun in an counterclockwise orbit). January 1, 2008 ina (Singapore) what direction does the earth rotate?east to west or west to east?and which direction (nort,south,east or west) is the axis of the earth slanted? The Earth rotates on its axis from West to East, and its axis is slanted about 23 degrees from the vertical. December 27, 2007 what s the effect when earts rotates on its axis The rotation of a planet on its axis is the cause of day and night. December 17, 2007 Karyn (Wisconsin) Why do we not feel the Earth's movement as it rotates? If you close your eyes when riding a car on a very straigh and very smooth road, you won't feel the motion. That is the same reason we don't feel Earth's motion.

November 7, 2007 Antony (Somerset in England) Are there any variations in the earth's orbit? My question is prompted by the evidence of the 1500 year global warming cycle but with no corresponding matching cycle of changes in the sun's radiance. I am asking if the sun/earth distance has occasional variances? Yes there are, and its relation with our planet climate is called The Milankovitch Theory. Please, visit this NOAA page for more information. November 5, 2007 sujakrishnan (India) Does the Earth moves in a North South direction? Yes, this "buoyancy" motion is one of many small motions of our planet. The two more important are the motion around the Sun and the rotation around its axis. September 17, 2007 how long does it take the earth to orbit the sun? One full orbit around the Sun is the definition of a year. August 21, 2007 How long does it take for the Earth to complete one orbit around the Sun? One full orbit of our planet around the Sun takes one year.

July 6, 2007 Bob (usa) What is the shape of the Orbit that the Earth gose around the sun? Like all planets in our solar system, the Earth is in an elliptical orbit around our Sun. In Earth's case, its orbit is nearly circular, so that the difference between Earth's farthest point from the Sun and its closest point is very small. More information in our webpage The Earth's Orbit . July 3, 2007 corey (Maryland) how does the earths rotation affect us? There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. Acting together, these two movements create variations in temperature, weather, and in the seasons. May 30, 2007 ABDUL (QATAR) why sun rises in the east?

If we imagine the Earth to be at the center of a large sphere (the celestial sphere), where the Sun, stars, etc. are located; because the Earth is rotating from west to the east, everything on the celestial sphere will apparently move from east to the west. May 10, 2007 abu (Canada) What causes seasonal changes?? During the year, the seasons change depending on the amount of sunlight reaching the Earth as it revolves around the Sun. The seasons are caused as the Earth, tilted on its axis, travels in a loop around the Sun each year. Summer happens in the hemisphere tilted towards the Sun, and winter happens in the hemisphere tilted away from the Sun. As the Earth travels around the Sun, the hemisphere that is tilted towards or away from the Sun changes. The hemisphere that is tilted towards the Sun is warmer because sunlight travels more directly to the Earthï¿½s surface so less gets scattered in the atmosphere. That means that when it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. The hemisphere tilted towards the Sun has longer days and shorter nights. Thatï¿½s why days are longer during the summer than during the winter.

More information in our web page Earth's Tilt Is the Reason for the Seasons! and the links therein. May 5, 2007 Smriti (India) Why does earth rotate about its own axis? The rotation of the Earth, and other planets, about their axis is a remanent of the rotation of the planetary nebula from where all were formed. March 7, 2007 Rosemarie I am searching for a model of the earths eccenticity. I am not sure what you mean by a model of the Earth's eccenticity, so here are some considerations: The orbit of the Earth is not a circle, but is very close! In mathematics, eccentricity is a parameter associated with every conic section. It can be seen as a measure of how much the section deviates from being circular. In particular, the eccentricity of a circle is zero, and the eccentricity of a (non-circle) ellipse is between 0 and 1. For our planet this parameter is 0.017, meaning an orbit very close to a circular shape. March 7, 2007 Annnaleise (California) What determines a year?

There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. March 7, 2007 achsah (NY/U.S) How does the movement of the earth cause day and night? There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights (because every time shows to the Sun a different side of the Earth). The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. Acting together, these two movements create variations in temperature, weather, and in the seasons.

February 28, 2007 vanessa (philippines) why are there places w/c have different seasons and what are the effects of the rotation and revolution of the earth and its connection to this seasons? In more or less degree thare are seasons all around the planet. The four seasons are better define at mid-latitudes. The tilt of Earth's rotational axis and the Earth's orbit work together to create the seasons. As the Earth travels around the Sun, it remains tipped in the same direction, towards the star Polaris. This means that sometimes the northern half of the Earth is pointing towards the Sun (summer), and sometimes it is pointing away (winter). A complete explanation of the seasons can be found in our web page The Seasons . February 5, 2007 jet (Philippines) what are the structural features of the earth's movement? There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun.

One revolution takes 365 ï¿½ days, or one year. Acting together, these two movements create variations in temperature, weather, and in the seasons. February 5, 2007 YAM (Philippines) what are the structural features of the earth's movement? There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. Acting together, these two movements create variations in temperature, weather, and in the seasons. January 29, 2007 Larry (IN/USA) Why does the earth move like the way it does and will it ever change in the future because me and my brother have a bet i say that it will probbly never and he says it will The answer to your question starts with the Big Bang. Matter spun off of this original explosion (much like water spins in smaller circles when you swirl your hand through it).

Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust. Squeezing made the cloud start to collapse, as gravity pulled the gas and dust together, forming a solar nebula. The planets and moons were formed from this solar nebula. The Earth and other planets continue to spin unless acted on by an outside force (a big comet hitting the planet, etc). January 19, 2007 Joey (N.J./US) How does winter solstice work? Due to the rotation of our planet around the Sun, the position of the Sun in the sky changes, in the north-south axis, over the course of the year due to the changing orientation of the Earth's rotation axes with respect to the Sun. The dates of maximum tilt of the Earth's equator correspond to the summer and winter solstice, and the dates of zero tilt to the vernal and autumnal equinox.

In the northern hemisphere, the Winter solstice is day of the year (near December 22) when the Sun is farthest south January 14, 2007 Brandon (findlay) how dose day and night occur There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. Acting together, these two movements create variations in temperature, weather, and in the seasons. January 3, 2007 dennis (durham england) howmany miles does the earth travel around the sun in one year? Although earth's orbit is an ellipse, the difference between the major (1 AU) and minor(0.983 AU) axes is minimum, and we can take the orbit as a circle with a radius = 1AU = 93 million miles.

The circumference = 2*Pi*r = 2*22/7*93*10^6 = 584.57 million miles (roughly). December 27, 2006 stefanie (maine) what does rotation mean? In a planetary sense, Rotation is a complete revolution around the planet axis. For example, the rotation period of our planet around its axis (Length of Day) is 24 hrs, and its revolution period around the Sun (Length of a Year) is 365 days 5 hrs. December 20, 2006 Roxanne ( England) Is the eath's orbit a perfect circle? Although the orbit of the Earth is not a circle, it is very close! In mathematics, eccentricity is a measure of how much the orbit deviates from being circular. In particular, the eccentricity of a circle is zero, and the eccentricity of a (non-circle) ellipse is between 0 and 1. For our planet this parameter is 0.017, meaning an orbit very close to a circular shape.

December 20, 2006 amber (england) why do we have night and day? There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. December 20, 2006 Leah (Australia) My teacher is asking to research the rotattion of the earth? Can you please help me? Earth has two important movements. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. December 13, 2006 How many mph does the Earth go around the sun?

The orbital speed of our planet is 29.8 km/s (~ 66 514 miles/hour) December 11, 2006 Ashley (Texas USA) How does the seasons change on Earth. The seasons are caused as the Earth, tilted on its axis, travels in a loop around the Sun each year. Summer happens in the hemisphere tilted towards the Sun, and winter happens in the hemisphere tilted away from the Sun. As the Earth travels around the Sun, the hemisphere that is tilted towards or away from the Sun changes. More information can be found at our web page Earth's Tilt Is the Reason for the Seasons! December 9, 2006 Dagmawit (Canada) What makes Day and Night There are two important movements that affect the Earth. The first is the rotation of the Earth around an invisible axis. It takes the Earth about 24 hours to finish one complete rotation. This motion is responsible for days and nights. The second important movement that affects the Earth is its revolution around the Sun. One revolution takes 365 ï¿½ days, or one year.

December 6, 2006 Aimee (Connecticut) How far is Mercury from Earth? Because all planets are constantly rotating around the Sun, it is useful to establish a frame to determine the average distance between two of them. Letï¿½s assume for this calculation that Mercury and Earth are aligned with the Sun, and use their average distance to the Sun to determine the average distance between them: Mercury average distance to the Sun: 57.9 million km (36.0 million miles) Earth average distance to the Sun: 149.0 million km (92.8 million miles) Difference (average distance between the two planets): 91.1 million km (56.8 million miles) November 27, 2006 michael (united states of america/north america) how far is the moon from the sun?

Because the Moon revolves around the Earth, the average distance to the Sun is the same for both: 149 000 000 km (92 800 000 miles) November 27, 2006 MANVI (delhi/india) what is occurance of day and night? Our planet has two important movements: the rotation of the Earth around its axis, which takes about 24 hours to finish. This rotation is the cause of days and nights. The second is the revolution around the Sun. One revolution takes 365 ï¿½ days, or one year. November 12, 2006 Maya (Indiana) What do you call the earths movement around the sun? Is it called "Orbit" The two main movements of the Earth are the rotation of the Earth around its axis (it takes 24 hours to complete one rotation), and the revolution of the Earth, or orbital motion, around the Sun (which takes 365 ï¿½ days, or 1 year, to complete).

November 9, 2006 Selina (Australia) What is the exact distance from the earth's equator to the sun in km's? The slightly elliptical orbit of the Earth around the Sun causes the Earth-Sun distance to vary along the year. The average distance has been calculated to be 149 476 000 Km. October 23, 2006 nompumelelo (south africa) how many days does the earth revolver around the sun The period in which our planet completes a revolution around the Sun is 1 year (365 hrs 56 min). For more interesting information and statistics about the Earth, visit our webpage Earth October 23, 2006 What is the distance between the earth and moon? How much time does take per revolution? Dear Ajitha The distance between our planet and moon changes continuously, but it has been calculated that the average Earth-Moon distance is about 385 000 km. Now, the period in which the Moon completes a revolution around the Earth is exactly 27.321661 "Earth days", commonly expressed as 27.3 days.

Thank you for visiting Windows to the Universe. November 21, 2000 Jarald (Ohio, USA) Why do seasons occur? Most people think the seasons are caused by the Earth being farther away or closer to the Sun. But, it's actually the tilt of the Earth and the motion of the Earth about the Sun that causes the seasons! Check it out! September 26, 2000 Jess (New Zealand) Do the chairs on a merry-go-round rotate or revolve? Chairs on a merry-go-round revolve around the center of the ride, just like the Earth revolves around the Sun! If each chair spun around itself, then the chair would be rotating. June 26, 2000 How do you measure the distance between Earth and the Sun? (Intermediate) - Curious About Astronomy? Ask an Astronomer How do you measure the distance between Earth and the Sun?

(Intermediate) (Intermediate) >" onclick="window.open(this.href,'win2','status=no,toolbar=no,scrollbars=yes,titlebar=no,menubar=no,resizable=yes,width=640,height=480,directories=no,location=no'); return false;" rel="nofollow"> How do astronomers calculate the distance of the Sun from the Earth, or the actual size of the Sun, or the speed of travel of Earth in its orbit around the Sun? Clearly, from an answer to one of these questions one can find out the answers to the others. But how do we find the first answer? Short version: What we actually measure is the distance from the Earth to some other body, such as Venus. Then we use what we know about the relations between interplanetary distances to scale that to the Earth-Sun distance. Since 1961 , we have been able to use radar to measure interplanetary distances - we transmit a radar signal at another planet (or moon or asteroid ) and measure how long it takes for the radar echo to return. Before radar, astronomers had to rely on other (less direct) geometric methods .

In more detail: The first step in measuring the distance between the Earth and the Sun is to find the relative distances between Earth and other planets. (For instance, what is the ratio of the Jupiter-Sun distance to the Earth-Sun distance?) So, let us say that the distance between Earth and the Sun is "a". Now, consider the orbit of Venus. To a first approximation, the orbits of Earth and Venus are perfect circles around the Sun, and the orbits are in the same plane. Take a look at the diagram below (not to scale). From the representation of the orbit of Venus, it is clear that there are two places where the Sun-Venus-Earth angle is 90 degrees. At these points, the line joining Earth and Venus will be a tangent to the orbit of Venus. These two points indicate the greatest elongation of Venus and are the farthest from the Sun that Venus can appear in the sky.

(More formally, these are the two points at which the angular separation between Venus and the Sun, as seen from Earth, reaches its maximum possible value.) Another way to understand this is to look at the motion of Venus in the sky relative to the Sun: as Venus orbits the Sun, it gets further away from the Sun in the sky, reaches a maximum apparent separation from the Sun (corresponding to the greatest elongation), and then starts going towards the Sun again. This, by the way, is the reason why Venus is never visible in the evening sky for more than about three hours after sunset or in the morning sky more than three hours before sunrise. Now, by making a series of observations of Venus in the sky, one can determine the point of greatest elongation. One can also measure the angle between the Sun and Venus in the sky at the point of greatest elongation. In the diagram, this angle will be the Sun-Earth-Venus angle marked as "e" in the right angled triangle.

Now, using trigonometry, one can determine the distance between Earth and Venus in terms of the Earth-Sun distance: (distance between Earth and Venus) = a × cos(e) Similarly, with a little more trigonometry: (distance between Venus and the Sun) = a × sin(e) The greatest elongation of Venus is about 46 degrees, so by this reasoning, the Sun-Venus distance is about 72% of the Sun-Earth distance. Similar observations and calculations yield the relative distance between the Sun and Mercury. (However, Mars and the outer planets are more complicated.) Historically, the first known person to use geometry to estimate the Earth-Sun distance was Aristarchus (c. 310-230 BC), in ancient Greece. He measured the angular separation of the Sun and the Moon when the Moon was half-illuminated to derive the distance between Earth and Sun in terms of the distance between the Earth and the Moon. His reasoning was correct, but his measurements were not. Aristarchus calculated that the Sun is about nineteen times farther than the Moon; it is actually about 390 times farther than the Moon.

Another ancient Greek astronomer, Eratosthenes (276-194 BC), estimated the distance between Earth and Sun to be either 4,080,000 stadia or 804,000,000 stadia . There is disagreement regarding the correct translation of Eratosthenes' value, and further disagreement over which length of a stadium was used by Eratosthenes. Various sources estimate that the length of a stadium (also called a stadion or stade), converted to modern units, is between 157 meters and 209 meters. Then 4,080,000 stades is less than 1% of the actual Earth-Sun distance, no matter which definition of a stade one chooses. However, 804,000,000 stadia is between 126 million and 168 million kilometers - a range which includes the actual Earth-Sun distance of (approximately) 150 million kilometers. So Eratosthenes may have found a fairly accurate value for the Earth-Sun distance (possibly with some luck), but we can't say for sure.

The first rigorous and accurate scientific measurement of the Earth-Sun distance was made by Cassini in 1672 by parallax measurements of Mars. He and another astronomer observed Mars from two places simultaneously. A century later, a series of observations of transits of Venus provided an even better estimate. Since 1961 , the distance to Venus can be determined directly, by radar measurements, where a series of radio waves is transmitted from Earth and is received after it bounces off Venus and comes back to Earth. By measuring the time taken for the radar echo to come back, the distance can be calculated, since radio waves travel at the speed of light. Once this Earth-Venus distance is known, the distance between Earth and the Sun can be calculated. As you have indicated, once the distance between Earth and Sun is known, one can calculate all the other parameters. We know that the Sun, as seen from Earth, has an angular diameter of about 0.5 degrees. Again, using trigonometry, the radius or diameter of the Sun can be calculated from the distance between Earth and Sun, a, as 2×Rsun = tan(0.5 degrees) × a.

Also, since we know the time taken by the Earth to go once around the Sun (P = 1 year), and the distance traveled by the Earth in this process (approximately 2πa, since Earth's orbit is nearly circular), we can calculate the average orbital speed of Earth as v = (2πa)/P. Anyway, the relevant numbers are: Earth-Sun distance, a = roughly 150 million km, defined as one Astronomical Unit ( AU ) Radius of the Sun, Rsun = roughly 700,000 km Orbital speed of Earth, v = roughly 30 km/s References: Jagadheep D. Pandian Jagadheep built a new receiver for the Arecibo radio telescope that works between 6 and 8 GHz. He studies 6.7 GHz methanol masers in our Galaxy . These masers occur at sites where massive stars are being born. He got his Ph.D from Cornell in January 2007 and was a postdoctoral fellow at the Max Planck Insitute for Radio Astronomy in Germany. After that, he worked at the Institute for Astronomy at the University of Hawaii as the Submillimeter Postdoctoral Fellow.

Jagadheep is currently at the Indian Institute of Space Scence and Technology. Similar Questions that might Interest You...

Question: Which body is on average, 150 million kilometres from the Sun?
Answer: THE EARTH