vania-janet/multiturn-rag-retrieval-data huggingface dataset:
Asteroid or Meteor: What's the Difference? | NASA Space Place – NASA Science for Kids
Asteroid or Meteor: What's the Difference? | NASA Space Place – NASA Science for Kids

asteroid-or-meteor

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Asteroid or Meteor: What's the Difference?

The Short Answer:

	An asteroid is a small rocky object that orbits the Sun. Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. A meteor is what happens when a meteoroid – a small piece of an asteroid or comet – burns up upon entering Earth’s atmosphere, creating a streak of light in the sky.
	

An asteroid is a small rocky object that orbits the Sun. A meteor is what happens when a small piece of an asteroid or comet, called a meteoroid, burns up upon entering Earth’s atmosphere. Read on to find out more and learn the difference between asteroids and comets, meteoroids and meteorites, and more!

Asteroids
An asteroid is a small rocky body that orbits the Sun.

A close-up view of Eros, an asteroid with an orbit that takes it somewhat close to Earth. The photo was taken by NASA’s Near Earth Asteroid Rendezvous - Shoemaker spacecraft in 2000. Image credit: NASA/JHUAPL
Asteroids are smaller than a planet, but they are larger than the pebble-size objects we call meteoroids. Most asteroids in our solar system are found in the main asteroid belt, a region between Mars and Jupiter. But they can also hang out in other locations around the solar system. For example, some asteroids orbit the Sun in a path that takes them near Earth.

Most asteroids in our solar system can be found in the asteroid belt, between Mars and Jupiter.
Meteoroids
Sometimes one asteroid can smash into another. This can cause small pieces of the asteroid to break off. Those pieces are called meteoroids. Meteoroids can also come from comets.

Meteors
If a meteoroid comes close enough to Earth and enters Earth’s atmosphere, it vaporizes and turns into a meteor: a streak of light in the sky.
What Is La Niña? | NASA Space Place – NASA Science for Kids
What Is La Niña? | NASA Space Place – NASA Science for Kids

la-nina

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What Is La Niña?

The Short Answer:

	La Niña is a weather pattern that begins in the Pacific Ocean. Warm ocean water and clouds move west during a La Niña. This means that places like Indonesia and Australia can get much more rain than usual. And places like the southwestern United States can be very dry.
	

The oceans play an important role in Earth's weather. Rain clouds normally form over warm ocean water. When strong winds cause this warm water to move, the clouds and storms move, too.
In normal conditions, winds above the Pacific Ocean gently push warm water west. That warm water travels from the west coast of South America all the way to Indonesia. As the warm water moves, cold water from the bottom of the ocean slowly rises up to take its place.

Credit: NASA/JPL-Caltech

But during La Niña...
In a La Niña year, the winds above the Pacific Ocean are much, much stronger than usual. This usually happens once every few years. The winds are so strong during a La Niña (Spanish for "the girl") that they push lots of warm ocean water west toward Indonesia. And that means that lots of cold water rises to the surface near South America.
This makes the water in the eastern Pacific Ocean degrees a few degrees colder than usual. Even this small change in the ocean's temperature can affect weather all over the world.

Drag the slider tool to see the differences between La Niña conditions and normal conditions in the Pacific Ocean.

Warm water moves west during a La Niña, and so do the clouds. This means that places like Indonesia and Australia can get much more rain than usual. And places like the southwestern United States can be very dry. La Niña weather conditions can also lead to more hurricanes and lightning in other parts of the world.
Thankfully, scientists can predict La Niña weather patterns up to a year before they occur.
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Long Shadows of Mongolian Mountains
In central Asia, jagged mountain peaks rise high above the steppe.
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Antarctic Ice Shelf Spawns Iceberg A-83
The Brunt Ice Shelf lost a large wedge of floating ice, the third sizeable iceberg to calve from the shelf in recent years.
Published May 23, 2024

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Sierra Snowpack Springs Back
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Months before the arrival of tourists and migrating birds, this high-elevation lake on the Tibetan Plateau was glazed with ice.
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Snow and ice influence climate by reflecting sunlight back into space. When it melts, snow is a source of water for drinking and vegetation; too much snowmelt can lead to floods. These maps show average snow cover by month.
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Make a Cloud Mobile! | NASA Space Place – NASA Science for Kids
The short skewer (and the clouds that are lowest in the atmosphere) will hang below the long skewer.Tip: You might have to try several hanging spots to get the clouds to hang level.

Now, tie a thread near the center of the long stick. Again, you may have to experiment to find the right spot to balance the weight of the mobile. Use this thread to hang the mobile somewhere that it can dance freely in the breeze!

Download a PDF of this activity.

Seeing through the clouds

CloudSat is an Earth satellite that studies the clouds in ways never before possible. CloudSat's instrument can see what’s inside the clouds. It sends out radar signals that bounce off the water in the clouds and then bounce back to the CloudSat instrument. This signal tells CloudSat how thick the clouds are and how much water they contain.
Knowing how clouds affect Earth's climate is very important. Do clouds trap heat and make Earth's surface warmer? Or do clouds' bright surfaces reflect enough sunlight back into space to make up for the heat they trap? These questions must be answered for scientists to be able to predict how Earth's climate may change.
Here is a CloudSat poster showing all the cloud types and comparing their altitudes in the sky.

Related Resources for Educators

Our World: Cloud Inspection
Clouds (Educator Guide for Clouds Spotlite video)
Clouds (Nearpod Lesson to go with Clouds Spotlite video)
Our World: What Is a Cloud?
Our World: Cool Clouds

 	article last updated April 17, 2020
 

Learn more about the clouds in your mobile:

Cumulonimbus clouds are the kings of all clouds, rising from low altitudes up to more than 12,000 meters (40,000 feet). They grow due to rising and falling currents, with their tops flattening out into an anvil shape. Cumulonimbus are a sure sign of severe weather, with heavy rain and possibly hail.

Cirrus clouds look like delicate strands or hooks. They are made mostly of ice crystals.
Cirrus are high clouds. They often look thin and patchy or feathery.
Sun-Earth Days 2013: Articles
This gave the solar wind open access to Mars' atmosphere resulting in atmospheric erosion from solar wind particles and the eventual loss of water and most of the rest of the atmosphere. So, the solar wind is in part responsible for the enormous climate change that Mars has experienced over the last few billion years. Other contributors to this process include meteor collisions and absorption of CO2 by the Martian surface.

Figure 15: Click to Enlarge

The shape of the sun's corona changes during this cycle. The shape of the corona is determined by the sun's magnetic field. High energy galactic cosmic rays (GCRs) from violent cosmic events such as super nova explosions are scattered by solar wind particles. Since the solar wind is emphasized during periods of high solar activity, fewer cosmic rays enter the inner solar system and so our atmosphere. Interactions between cosmic rays and Earth's atmosphere produce increased levels of Carbon-14 (14C). This increase in Carbon-14 provides historic records of solar cycles dating back many thousands of years. These records indicate that we are now in a relatively high period of overall solar activity and that many disruptions in the solar cycle have happened in the past. For reasons still not well understood, these disruptions (e.g. Maunder Minimum) have in some cases been correlated with decreases in global temperatures and even mini ice ages.
The amount of solar ultraviolet radiation varies by as much as 400% over the course of the solar cycle, being highest during solar max. However, increased UV also modifies the chemistry in the stratosphere to produce more ozone (O3) which is an effective UV absorber. So, the net result to us hear on the surface is about zero.
Auroras
Variations in solar activity play important roles in our daily lives. We already know that the interactions between the magnetic field of the solar wind and the Earth's magnetosphere result in beautiful auroras seen in high northern and southern latitudes. These aurora (Aurora Borialis and Aurora Australis) are roughly symmetrical and are driven by similar processes that drive auroras on the outer planets. Auroras have been observed locally in the atmospheres of Mars and Venus as well. Neither planet having a global magnetic field.
Glossary | NASA Space Place – NASA Science for Kids
It has very powerful gravitational force nearby because the whole mass of a star is pulled into one object just a few miles across.

Oort Cloud: A spherical shell around our solar system. It may contain more than a trillion icy bodies. Long-period comets (which take more than 200 years to orbit the sun) come from the Oort Cloud. 

Orbit: The curved path that a planet, satellite, or spacecraft moves as it circles around another object.
Ozone layer: A part of Earth’s atmosphere that absorbs lots of the sun’s ultraviolet radiation. It is made of a gas called ozone, which is a molecule of three oxygen atoms. 
Particle: A tiny amount or small piece of something. 
Planet: A large body in outer space that circles around the sun or another star. 
Pulsar: An object, thought to be a rapidly rotating neutron star. It releases short pulses of radio waves and other electromagnetic radiation.
Quasar: Compact area in the center of a massive galaxy that is around a supermassive black hole. They are some of the brightest objects in the universe and can be observed across the entire electromagnetic spectrum.

Radiation: The energy or particles released from sources like radioactive materials, explosions, and chemical reactions. This includes energy waves on the electromagnetic spectrum.

Radio waves: Part of the electromagnetic spectrum. Radio waves are around us here on Earth, and they’re out in space too. These waves are low energy. We use them every time we listen to the radio. They’re used to talk to satellites, too. They are also common in outer space, since they are sent out by forming stars, pulsars, supernovae, the sun, and even colliding galaxies.
Radioactive: How we describe some atoms that are unstable. They change into different kinds of atoms and release lots of energy.

Satellite: An object that orbits another object. A moon is actually a satellite. We also say satellite to refer to spacecraft people build that orbit Earth, other planets, moons, asteroids, or other objects out in space. 
Solar flare: A burst of energy and particles from the sun. It releases gases, radiation waves, and magnetic storms.
Collection - ABCs from Space
Spring Bloom in New Zealand Waters
A phytoplankton bloom colored the waters east of New Zealand on October 25, 2009.
Published Oct 28, 2009
 

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Akimiski Island, Canada
Scraped clean and weighted down for thousands of years by Pleistocene ice sheets, Akimiski Island in James Bay provides a case study of how Earth's land surfaces evolve following glaciation. During the last ice age, this small island was buried under several thousand meters ice, but since its retreat, the island has rebounded (risen in elevation) and new beach areas have emerged, streams and lakes have formed, and trees and other vegetation have colonized the new territory.
Published Apr 15, 2008
 

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Lonar Crater, India
India’s Lonar Crater began causing confusion soon after it was identified. Lonar Crater sits inside the Deccan Plateau—a massive plain of volcanic basalt rock leftover from eruptions some 65 million years ago. Its location in this basalt field suggested to some geologists that it was a volcanic crater. Today, however, Lonar Crater is understood to result from a meteorite impact that occurred between 35,000 and 50,000 years ago.
Published Apr 13, 2008
 

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Tenoumer Crater, Mauritania
Deep in the Sahara Desert lies a crater. Nearly a perfect circle, it is 1.9 kilometers (1.2 miles) wide, and sports a rim 100 meters (330 feet) high. Modern geologists long debated what caused this crater, some of them favoring a volcano. But closer examination of the structure revealed that the crater’s hardened “lava” was actually rock that had melted from a meteorite impact.
Published Feb 17, 2008
 

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Mackenzie River Delta, Canada
Canada’s Mackenzie River, the country’s longest, spills out of Great Slave Lake, just north of the border between Alberta and Northwest Territories.
Published Dec 20, 2007
 

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Andaman Islands, Bay of Bengal
Catalog of Earth Satellite Orbits
The Baikonur Cosmodrome (right), located at 49° north, is frequently used to launch satellites into polar and Molniya orbits, as well as to send astronauts and supplies to the International Space Station. [Photographs ©2008 ESA/CNES/ARIANESPACE/Activité Photo Optique Video CSG (left) and courtesy NASA (right).]

Maintaining Orbit
Once a satellite is in orbit, it usually takes some work to keep it there. Since Earth isn’t a perfect sphere, its gravity is stronger in some places compared to others. This unevenness, along with the pull from the Sun, Moon, and Jupiter (the solar system’s most massive planet), will change the inclination of a satellite’s orbit. Throughout their lifetime, GOES satellites have to be moved three or four times to keep them in place. NASA’s low Earth orbit satellites adjust their inclination every year or two to maintain a Sun-synchronous orbit.
Satellites in a low Earth orbit are also pulled out of their orbit by drag from the atmosphere. Though satellites in low Earth orbit travel through the uppermost (thinnest) layers of the atmosphere, air resistance is still strong enough to tug at them, pulling them closer to the Earth. Earth’s gravity then causes the satellites to speed up. Over time, the satellite will eventually burn up as it spirals lower and faster into the atmosphere or it will fall to Earth.
Atmospheric drag is stronger when the Sun is active. Just as the air in a balloon expands and rises when heated, the atmosphere rises and expands when the Sun adds extra energy to it. The thinnest layer of atmosphere rises, and the thicker atmosphere beneath it lifts to take its place. Now, the satellite is moving through this thicker layer of the atmosphere instead of the thin layer it was in when the Sun was less active. Since the satellite moves through denser air at solar maximum, it faces more resistance. When the Sun is quiet, satellites in low Earth orbit have to boost their orbits about four times per year to make up for atmospheric drag. When solar activity is at its greatest, a satellite may have to be maneuvered every 2-3 weeks.
October | 2014 | Terra
Is more energy being absorbed by Earth than is being lost to space? If so, what happens to the excess energy?
For seventeen years, scientists have been examining this balance sheet with a series of space-based sensors known as Clouds and the Earth’s Radiant Energy System, or CERES. The instruments use scanning radiometers to measure both the shortwave solar energy reflected by the planet (albedo) and the longwave thermal energy emitted by it. Read more

Expanding Burn Scar in Northern Territory

Posted on October 21, 2014 by Tassia Owen 
	Posted in News and Events 

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response Team at NASA GSFC. Caption by Adam Voiland, with information from Daniel Lindsey (NOAA) and Rick McRae (Australian Capital Territory Emergency Services Agency).
The intense bushfires that strike southern Australia in the summer usually attract the most headlines, but the country’s largest and most frequent blazes actually occur in northern Australia in the spring. In fact, in terms of sheer area burned, satellite observations show that over 98 percent of large fires in Australia occur well outside of densely populated southeastern and southwestern parts of the country.
A fire that began burning in Northern Territory on September 10, 2014, offers a prime example of just how expansive fires from this part of the continent can become. After racing through grasslands for just a few weeks, the fire had charred an area about the size of Massachusetts by October 8, 2014.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this sequence of images showing the progression of the fire.  Read more

NASA Study Finds Earth’s Ocean Abyss Has Not Warmed

Posted on October 7, 2014 by Tassia Owen 
	Posted in News and Events 

While the upper part of the world’s oceans continue to absorb heat from global warming, ocean depths have not warmed measurably in the last decade. This image shows heat radiating from the Pacific Ocean as imaged by the NASA’s Clouds and the Earth’s Radiant Energy System instrument on the Terra satellite. (Blue regions indicate thick cloud cover.)
What Causes the Seasons? | NASA Space Place – NASA Science for Kids
What Causes the Seasons? | NASA Space Place – NASA Science for Kids

seasons

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What Causes the Seasons?

The Short Answer:

	Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.
	

It's all about Earth's tilt!
Many people believe that Earth is closer to the Sun in the summer and that is why it is hotter. And, likewise, they think Earth is farthest from the Sun in the winter.
Although this idea makes sense, it is incorrect.
It is true that Earth's orbit is not a perfect circle. It is a bit lop-sided. During part of the year, Earth is closer to the Sun than at other times. However, in the Northern Hemisphere, we are having winter when Earth is closest to the Sun and summer when it is farthest away! Compared with how far away the Sun is, this change in Earth's distance throughout the year does not make much difference to our weather.
There is a different reason for Earth's seasons.
Earth's axis is an imaginary pole going right through the center of Earth from "top" to "bottom." Earth spins around this pole, making one complete turn each day. That is why we have day and night, and why every part of Earth's surface gets some of each.
Earth has seasons because its axis doesn't stand up straight. 
But what caused Earth to tilt?

Long, long ago, when Earth was young, it is thought that something big hit Earth and knocked it off-kilter. So instead of rotating with its axis straight up and down, it leans over a bit.
By the way, that big thing that hit Earth is called Theia. It also blasted a big hole in the surface.
How Do We Launch Things Into Space? | NASA Space Place – NASA Science for Kids
The exhaust pushes out of a rocket’s engine down toward the ground. That’s the action force. In response, the rocket begins moving in the opposite direction, lifting off the ground. That’s the reaction force.

Once a rocket launches, will it keep going?
It’s not that simple. Earth’s gravity is still pulling down on the rocket. When a rocket burns propellants and pushes out exhaust, that creates an upward force called thrust. To launch, the rocket needs enough propellants so that the thrust pushing the rocket up is greater than the force of gravity pulling the rocket down. 

Credit: NASA/JPL-Caltech

A rocket needs to speed up to at least 17,800 miles per hour—and fly above most of the atmosphere, in a curved path around Earth. This ensures that it won’t be pulled back down to the ground. But what happens next is different, depending on where you want to go.

How to Orbit Earth:
Let’s say you want to launch a satellite that orbits Earth. The rocket will launch, and when it gets to a specific distance from Earth, it will release the satellite.

Credit: NASA/JPL-Caltech

The satellite stays in orbit because it still has momentum—energy it picked up from the rocket—pulling it in one direction. Earth’s gravity pulls it in another direction. This balance between gravity and momentum keeps the satellite orbiting around Earth.

Credit: NASA/JPL-Caltech

Satellites that orbit close to Earth feel a stronger tug of Earth’s gravity. To stay in orbit, they must travel faster than a satellite orbiting farther away.
The International Space Station orbits about 250 miles above the Earth and travels at a speed of about 17,150 miles per hour. Compare that to the Tracking and Data Relay Satellites, which help us get information to and from other NASA missions. These satellites orbit at a height of more than 22,000 miles and travel much slower—about 6,700 miles per hour—to maintain their high orbit.

Credit: NASA/JPL-Caltech

How to Get to Other Planets: