Sun-Earth Day is a joint educational program established in 2000 by NASA and ESA. The goal of the program is to popularize the knowledge about the Sun, and the way it influences life on Earth, among students and the public.The day itself is mainly celebrated in the United States near the time of the spring equinox. However, the Sun-Earth Day event actually runs throughout the year, with a different theme being chosen each year.
The selection of each year's theme often corresponds to events for that year.Every theme is supported by free educational plans for both informal and formal educators. Here is a list of themes by year:
|2001||Having a Solar Blast|
|2002||Celebrate the Equinox|
|2003||Live from the Aurora|
|2005||Ancient Observatories Timeless Knowledge|
|2006||Eclipse: In a Different Light|
|2007||Living in the Atmosphere of the Sun|
|2008||Space Weather Around the World|
|2009||Our Sun, Yours to Discover|
|2011||March 19, 2011||Ancient Mysteries; Future Discoveries.|
|2012||June 5, 2012||Transit of Venus|
|2013||Solar Max – Storm Warning!|
|2014||[ data unknown/missing ]|
|2015||[ data unknown/missing ]|
|2016||[ data unknown/missing ]|
|2017||[ data unknown/missing ]|
Venus is the second planet from the Sun. It is named after the Roman goddess of love and beauty. As the second-brightest natural object in the night sky after the Moon, Venus can cast shadows and, rarely, is visible to the naked eye in broad daylight. Venus lies within Earth's orbit, and so never appears to venture far from the Sun, either setting in the west just after dusk or rising in the east a bit before dawn. Venus orbits the Sun every 224.7 Earth days. With a rotation period of 243 Earth days, it takes longer to rotate about its axis than any planet in the Solar System and rotates in the opposite direction to all but Uranus. Venus does not have any natural satellites, a distinction it shares only with Mercury among planets in the Solar System.
The 22nd (twenty-second) century is the next century in the Anno Domini or Common Era in accordance with the Gregorian calendar. It will begin on January 1, 2101, and will end on December 31, 2200. It is distinct from the century known as the 2100s which will begin on January 1, 2100, and will end on December 31, 2199.
In astronomy, a conjunction occurs when two astronomical objects or spacecraft have either the same right ascension or the same ecliptic longitude, usually as observed from Earth. The astronomical symbol for conjunction is ☌ and handwritten
A solar flare is a sudden flash of increased brightness on the Sun, usually observed near its surface and in close proximity to a sunspot group. Powerful flares are often, but not always, accompanied by a coronal mass ejection. Even the most powerful flares are barely detectable in the total solar irradiance.
MESSENGER was a NASA robotic spacecraft that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for "MErcury Surface, Space ENvironment, GEochemistry, and Ranging", and a reference to the messenger god Mercury from Roman mythology.
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Venus can be seen from Earth as a small black dot moving across the face of the Sun. The duration of such transits is usually several hours. A transit is similar to a solar eclipse by the Moon. While the diameter of Venus is more than three times that of the Moon, Venus appears smaller, and travels more slowly across the face of the Sun, because it is much farther away from Earth.
A transit of Mercury across the Sun takes place when the planet Mercury passes directly (transits) between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Mercury appears as a tiny black dot moving across the disk of the Sun.
The 2012 transit of Venus, when the planet Venus appeared as a small, dark spot passing across the face of the Sun, began at 22:09 UTC on 5 June 2012, and finished at 04:49 UTC on 6 June. Depending on the position of the observer, the exact times varied by up to ±7 minutes. Transits of Venus are among the rarest of predictable celestial phenomena and occur in pairs. Consecutive transits per pair are spaced 8 years apart, and consecutive pairs occur more than a century apart: The previous transit of Venus took place on 8 June 2004 ; the next pair of transits will occur on 10–11 December 2117 and December 2125 within the 22nd century.
A transit of Deimos across the Sun as seen from Mars occurs when Deimos passes directly between the Sun and a point on the surface of Mars, obscuring a small part of the Sun's disc for an observer on Mars. During a transit, Deimos can be seen from Mars as a small dark spot rapidly moving across the Sun's face.
Observations of the planet Venus include those in antiquity, telescopic observations, and from visiting spacecraft. Spacecraft have performed various flybys, orbits, and landings on Venus, including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth, compared to other planets, but the surface of Venus is obscured by an atmosphere opaque to visible light.
A solar eclipse occurs when a portion of the Earth is engulfed in a shadow cast by the Moon which fully or partially blocks sunlight. This occurs when the Sun, Moon and Earth are aligned. Such alignment coincides with a new moon (syzygy) indicating the Moon is closest to the ecliptic plane. In a total eclipse, the disk of the Sun is fully obscured by the Moon. In partial and annular eclipses, only part of the Sun is obscured.
The atmosphere of Venus is the layer of gases surrounding Venus. It is composed primarily of carbon dioxide and is much denser and hotter than that of Earth. The temperature at the surface is 740 K, and the pressure is 93 bar (9.3 MPa), roughly the pressure found 900 m (3,000 ft) underwater on Earth. The Venusian atmosphere supports opaque clouds made of sulfuric acid, making optical Earth-based and orbital observation of the surface impossible. Information about the topography has been obtained exclusively by radar imaging. Aside from carbon dioxide, the other main component is nitrogen. Other chemical compounds are present only in trace amounts.
The Active Cavity Radiometer Irradiance Monitor Satellite, or ACRIMSAT is a defunct satellite and instrument that was one of the 21 observational components of NASA's Earth Observing System program. The instrument followed upon the ACRIM1 and ACRIM2 instruments that were also launched on multi-instrument satellite platforms. ACRIMSAT was launched on 20 December 1999 from Vandenberg Air Force Base as the secondary payload on the Taurus rocket that launched KOMPSAT. It was placed into a high inclination, 700 km. sun-synchronous orbit from which the ACRIM3 instrument monitored total solar irradiance (TSI). Contact with the satellite was lost on 14 December 2013.
The Parker Solar Probe is a NASA robotic spacecraft launched in 2018, with the mission of repeatedly probing and making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii from the center of the Sun and by 2025 will travel, at closest approach, as fast as 690,000 km/h (430,000 mph), or 0.064% the speed of light.
In contemporary history, the third millennium of the anno Domini or Common Era in the Gregorian calendar is the current millennium spanning the years 2001 to 3000. It is differentiated from the commonly-used "2000s millennium" which includes the year 2000 but not 3000.
In astronomy, a syzygy is a roughly straight-line configuration of three or more celestial bodies in a gravitational system.
Kepler-69c is a confirmed super-Earth extrasolar planet, likely rocky, orbiting the Sun-like star Kepler-69, the outermost of two such planets discovered by NASA's Kepler spacecraft. It is located about 2,430 light-years from Earth.
A coronal cloud is the cloud of hot plasma gas surrounding a coronal mass ejection. It is usually made up of protons and electrons. When a coronal mass ejection occurs at the Earth's Sun, it is the coronal cloud that usually reaches Earth and causes damage to electrical equipment and space satellites, not the ejection or flare itself. The damage is mostly the result of the high amount of electricity moving through the atmosphere.
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