paragraph_text: The Dalton Minimum was a period of low sunspot count, representing low solar activity, named after the English meteorologist John Dalton, lasting from about 1790 to 1830 or 1796 to 1820, corresponding to the period solar cycle 4 to solar cycle 7.

paragraph_text: Valles Marineris (Latin for "Mariner Valleys", named after the "Mariner 9" Mars orbiter of 1971–72 which discovered it) is a system of canyons that runs along the Martian surface east of the Tharsis region. At more than long, wide and up to deep, Valles Marineris is one of the largest canyons of the Solar System, surpassed in length only by the rift valleys of Earth.

paragraph_text: The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometers, i.e. 109 times that of Earth, and its mass is about 330,000 times that of Earth, accounting for about 99.86% of the total mass of the Solar System. About three quarters of the Sun's mass consists of hydrogen (~ 73%); the rest is mostly helium (~ 25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.

paragraph_text: Goddard Space Flight Center is NASA's first, and oldest, space center. It is named after Dr. Robert H. Goddard, the father of modern rocketry. Throughout its history, the center has managed, developed, and operated many notable missions, including the Cosmic Background Explorer, the Hubble Space Telescope, the Tracking and Data Relay Satellite System (TDRSS), the Lunar Reconnaissance Orbiter, and the Solar Dynamics Observatory.

paragraph_text: The common features of passive solar architecture are orientation relative to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and thermal mass. When these features are tailored to the local climate and environment they can produce well-lit spaces that stay in a comfortable temperature range. Socrates' Megaron House is a classic example of passive solar design. The most recent approaches to solar design use computer modeling tying together solar lighting, heating and ventilation systems in an integrated solar design package. Active solar equipment such as pumps, fans and switchable windows can complement passive design and improve system performance.

paragraph_text: Jupiter has been called the Solar System's vacuum cleaner, because of its immense gravity well and location near the inner Solar System. It receives the most frequent comet impacts of the Solar System's planets. It was thought that the planet served to partially shield the inner system from cometary bombardment. However, recent computer simulations suggest that Jupiter does not cause a net decrease in the number of comets that pass through the inner Solar System, as its gravity perturbs their orbits inward roughly as often as it accretes or ejects them. This topic remains controversial among scientists, as some think it draws comets towards Earth from the Kuiper belt while others think that Jupiter protects Earth from the alleged Oort cloud. Jupiter experiences about 200 times more asteroid and comet impacts than Earth.A 1997 survey of early astronomical records and drawings suggested that a certain dark surface feature discovered by astronomer Giovanni Cassini in 1690 may have been an impact scar. The survey initially produced eight more candidate sites as potential impact observations that he and others had recorded between 1664 and 1839. It was later determined, however, that these candidate sites had little or no possibility of being the results of the proposed impacts.More recent discoveries include the following:

paragraph_text: Olympus Mons (/ əˌlɪmpəs ˈmɒnz, oʊ -, - ˈmɒns /; Latin for Mount Olympus) is a very large shield volcano on the planet Mars. By one measure, it has a height of nearly 22 km (13.6 mi or 72,000 ft). Olympus Mons stands about two and a half times as tall as Mount Everest's height above sea level. It is the tallest mountain of all planets and other rounded bodies in the Solar System, and is the second tallest mountain in the Solar System overall, after Rheasilvia on the Asteroid Vesta. It is the youngest of the large volcanoes on Mars, having formed during Mars's Hesperian Period. It is currently the largest volcano discovered in the Solar System and had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for ``Olympic Snow ''). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.

paragraph_text: Charles Thomas Kowal (November 8, 1940 – November 28, 2011) was an American astronomer known for his observations and discoveries in the Solar System. As a staff astronomer at Caltech's Mount Wilson and Palomar Mountain observatories between 1961 and 1984, he found the first of a new class of Solar System objects, the centaurs, discovered two moons of the planet Jupiter, and discovered or co-discovered a number of asteroids, comets and supernovae. He was awarded the James Craig Watson Medal for his contributions to astronomy in 1979.

paragraph_text: Wonders of the Solar System is a 2010 television series co-produced by the BBC and Science Channel, and hosted by physicist Brian Cox. "Wonders of the Solar System" was first broadcast in the United Kingdom on BBC Two on 7 March 2010. The series comprises five episodes, each of which focuses on an aspect of the Solar System and features a 'wonder' relevant to the theme. The series was described as one of the most successful to appear on BBC Two in recent years. An accompanying book with the same name was also published.

paragraph_text: It is an important source of renewable energy and its technologies are broadly characterized as either passive solar or active solar depending on the way they capture and distribute solar energy or convert it into solar power. Active solar techniques include the use of photovoltaic systems, concentrated solar power and solar water heating to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

paragraph_text: Meteorites from Antarctica are an important area of study of material formed early in the solar system; most are thought to come from asteroids, but some may have originated on larger planets. The first meteorite was found in 1912, and named the Adelie Land meteorite. In 1969, a Japanese expedition discovered nine meteorites. Most of these meteorites have fallen onto the ice sheet in the last million years. Motion of the ice sheet tends to concentrate the meteorites at blocking locations such as mountain ranges, with wind erosion bringing them to the surface after centuries beneath accumulated snowfall. Compared with meteorites collected in more temperate regions on Earth, the Antarctic meteorites are well-preserved.

paragraph_text: Fierbinţi Solar Park, a large thin-film photovoltaic (PV) power system, is being built on a 4 ha plot of land near the Fierbinți-Târg commune in Romania. The power plant will be a 10-megawatt solar power system using state-of-the-art thin film technology, and should be finished by the end of 2012. The solar park is expected to supply 4,000 MWh of electricity per year.

paragraph_text: Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Solar System. Historically, Heliocentrism was opposed to geocentrism, which placed the Earth at the center. The notion that the Earth revolves around the Sun had been proposed as early as the 3rd century BC by Aristarchus of Samos, but at least in the medieval world, Aristarchus's Heliocentrism attracted little attention -- possibly because of the loss of scientific works of the Hellenistic Era.

paragraph_text: NGC 210 is a barred spiral galaxy located roughly 67 million light-years from the Solar System in the constellation Cetus. It was discovered on October 3, 1785 by William Herschel and later added to the New General Catalogue.

paragraph_text: Solgränd (Swedish: "Sun Alley") is an alley in Gamla stan, the old town of Stockholm, Sweden. It connects the Stortorget square to the street Prästgatan. It is a parallel street to Storkyrkobrinken, Ankargränd, Spektens gränd, and Kåkbrinken.

paragraph_text: Solar power in Germany consists almost exclusively of photovoltaics (PV) and accounted for an estimated 6.2 to 6.9 percent of the country's net - electricity generation in 2016. About 1.5 million photovoltaic systems were installed around the country in 2014, ranging from small rooftop systems, to medium commercial and large utility - scale solar parks. Germany's largest solar farms are located in Meuro, Neuhardenberg, and Templin with capacities over 100 MW. Solar heating does not use solar energy for power generation and is therefore not included in this article.

paragraph_text: Dorsa Barlow is a wrinkle ridge system on the Moon, in Mare Tranquilitatis near the border with Mare Serenitatis, centered at . It is about 110 km long and was named after British crystallographer William Barlow in 1976.

paragraph_text: Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 88 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger to the gods.

paragraph_text: Arsia Mons is the southernmost of three volcanos (collectively known as Tharsis Montes) on the Tharsis bulge near the equator of the planet Mars. To its north is Pavonis Mons, and north of that is Ascraeus Mons. The tallest volcano in the Solar System, Olympus Mons, is to its northwest. Its name comes from a corresponding albedo feature on a map by Giovanni Schiaparelli, which he named in turn after the legendary Roman forest of Arsia Silva.

paragraph_text: The birth of the modern widely accepted theory of planetary formation -- the solar nebular disk model (SNDM) -- can be traced to the Soviet astronomer Victor Safronov. His 1969 book Evolution of the protoplanetary cloud and formation of the Earth and the planets, which was translated to English in 1972, had a long - lasting effect on the way scientists think about the formation of the planets. In this book almost all major problems of the planetary formation process were formulated and some of them solved. Safronov's ideas were further developed in the works of George Wetherill, who discovered runaway accretion. While originally applied only to the Solar System, the SNDM was subsequently thought by theorists to be at work throughout the Universe; as of 1 December 2017 astronomers have discovered 3,710 extrasolar planets in our galaxy.

Question: When was the star to which Solgränd is named after discovered to be the center of the solar system?
Answer: as early as the 3rd century BC