What's Up - June 2015
What's Up for June. Planets, dwarf planets, asteroids, and the Milky Way. Hello and welcome. I'm Jane Houston Jones from NASA's Jet Propulsion Laboratory in Pasadena, California.
The month starts off with a beautiful close pairing of the moon and Saturn. They rise together in the eastern sky an hour after sunset on the first of June.
The dwarf planet Pluto, largest of the Kuiper Belt objects, will be near the moon on Friday, June 5. But the moon will be 3 days past full and very bright. The moonlight will make seeing Pluto practically impossible. But it's still nice to know where it is. NASA's New Horizons will become Earth's first spacecraft to reach Pluto and its system of moons on July 14 after a 9-year journey spanning 3 billion miles.
On June 11 asteroid hunters should be able to spot Pallas, the second asteroid to be discovered. When Pallas was discovered in 1802, it was classified as a planet, as were several other asteroids. The discovery of many more asteroids in the mid-1800s eventually led to their reclassification from planets to asteroids.
Ceres, the first asteroid discovered, is now classified as a dwarf planet instead of an asteroid. Ceres meets 2 of the 3 requirements of planethood. It orbits the sun and it's round. But other bodies share its orbit. For Ceres, other asteroids share its orbit. For Pluto, it's other Kuiper Belt objects. Ceres reaches opposition at the end of the month when it appears opposite the sun in the sky. When the sun sets in the west Ceres rises in the East and is visible all night long. To see Ceres, which shines at a brightness of magnitude 7, you'll have to use binoculars or telescopes.
Speaking of dawn, NASA's Dawn spacecraft reached its first science orbit around Ceres last month. It will map the surface from now through June 2016 and attempt to determine what the dwarf planet is made of.
Here's what else is visible this month. Jupiter and Venus start the month about 20 degrees from each other. But by the end of June they're only 2 degrees apart. Watch Venus pass the bright Beehive star cluster M44 from a moderately dark sky on June 13 and 14. Binoculars will help to see the dazzling stars in the cluster. Saturn is visible all night long. It's definitely worth attending a local star party to see the ringed planet through a telescope, if you haven't done it already.
Catch all 3 bright planets in the evening. Saturn in the southern sky as Jupiter and Venus set in the northwest.
You can learn about small worlds: asteroids, dwarf planets and comets at: solarsystem.nasa.gov
And you can learn about the New Horizons and Dawn missions and all of NASA's other missions at: www.nasa.gov
That's all for this month. I'm Jane Houston Jones.