Ceres at opposition, coming up November 27 (earthsky.org)
Posted by Kelly Kizer Whitt
September 20, 2021
Ceres was the first asteroid discovered, in 1801. The International Astronomical Union reclassified it and Pluto as dwarf planets in 2006. Ceres is the largest object in the asteroid belt between Mars and Jupiter. It’s the only world in the asteroid belt with enough mass – and therefore enough self-gravity – to pull itself into the shape of a ball. So Ceres is the only dwarf planet in the asteroid belt, or even inside the orbit of Neptune, for that matter. In 2021, Ceres will be at opposition – opposite the sun in our sky – on November 27. At that time, it’ll rise at sunset and set at sunrise. It’s coming up later at night now (mid-September), but will be rising earlier. Now is the beginning of the best time in 2021 to view Ceres.
Ceres is about 600 miles (1,000 km) across, or about 1/4 the size of our moon. With its size wedged somewhere between an asteroid and a planet, Ceres was a target for study by the Dawn spacecraft.
Dawn arrived at Ceres in 2015. The spacecraft caused a stir while approaching Ceres, when it began to capture images of bright spots on the dwarf planet’s surface. People joked that the spots looked like alien headlights. But they turned out to be salt deposits from salty water inside the planet. Dawn also found a 2.5-mile (4,000-meter) high mountain called Ahuna Mons.
If you have a telescope or good binoculars, now is the time to start watching Ceres. Note that the name asteroid means starlike. From Earth, Ceres looks like a star. But because it’s so close to us, it can be seen to move in front of the stars from night to night.
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View larger. | Throughout September, October and November 2021, Ceres (inside yellow circle) will be meandering through Taurus the Bull. Taurus ascends in the east in the middle of the night in mid-September. But it’ll rise earlier each evening. Ceres will cut across the V-shaped Hyades star cluster in Taurus before its opposition on November 27, 2021. Chart via Dominic Ford/ TheSkyLive. Go to this page at TheSkyLive to view a more detailed star chart showing a telescopic view of Ceres.
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The easiest time to find Ceres in 2021 might be the first few days of November. Magnitude 7.5 Ceres will pass less than a moon’s width from Aldebaran in Taurus around these evenings. If you focus binoculars or a telescope on Aldebaran, the point of light close to the star will be Ceres. Check out the finder maps below.
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more: https://earthsky.org/astronomy-essentials/ceres-at-opposition/?utm_source=EarthSky+News