Geeks in Space: Dawn and the Vestal Virgin
NASA's Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on July 9, 2011. It was taken from a distance of about 26,000 miles (41,000 kilometers) away from Vesta, which is also considered a protoplanet because it is a large body that almost became a planet. Each pixel in the image corresponds to roughly 2.4 miles (3.8 kilometers). Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
At approximately 10pm Pacific time tonight, NASA’s spacecraft Dawn should enter orbit around Vesta, marking the first time a human built craft orbits an asteroid. First launched in 2007, Dawn’s engineers have spent the last four years nudging the craft’s trajectory to match Vesta’s orbit around the sun. Rather than using a propulsive burn to put spacecraft in orbit, the asteroid itself will gently capture Dawn as its gravity pulls her in.
Dawn will then spend the next year studying Vesta while scientists hope to gain a better understanding of the early solar system. After that, she will break orbit around Vesta and head for the dwarf planet Ceres in July 2012, making her the first spacecraft to orbit two different bodies in our solar system.
4 Vesta is the second-most-massive object in the asteroid belt and comprises 9% of the mass of the entire belt. 1 Ceres is the largest and most massive body in the asteroid belt and the only dwarf planet within the belt. Dawn’s mission to Ceres will help determine if its icy crust hides an ocean of liquid water underneath. Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory.
Neptune’s Birthday
Did you know that the planet Neptune was discovered only one year ago? One Neptune year, that is. First discovered on July 12, 1846, Neptune completed one orbit on Tuesday. It is the most distant major planet in the solar system and 30 times farther from the sun than the Earth. It is also like Earth in that it has seasons due to its axis being tilted 29 degrees (Earth’s axis tilts 23 degrees), however each of Neptune’s seasons lasts 40 years. Not visible to the naked eye, Neptune can be seen with strong binoculars or a small telescope pointed at the constellation Aquarius, close to the boundary near Capricorn.
Gassing up at the Pump
NASA's Juno spacecraft passes in front of Jupiter in this artist's depiction. The Juno mission is the first of NASA's three planetary missions launching this year, making 2011 one of the busiest ever in planetary exploration. Image credit: NASA/JPL-Caltech
The Juno spacecraft completed fueling up its propulsion system in preparation for its launch to Jupiter next month. Hydrazine is the main fuel for the craft because of its ability to store energy. When mixed with an oxidizer, hydrazine ignites in the engine produces an incredible amount of energy. These bursts will fuel four major maneuvers including inserting the craft into orbit around Jupiter in 2016. The fueling process makes the Juno 99% ready for launch.
Juno is part of NASA’s New Frontiers mission and will study Jupiter’s composition, gravity and magnetic fields and the polar magnetosphere. The New Frontiers mission is a series of missions designed to explore Jupiter, Venus and Pluto. In addition to Juno, the New Horizons mission launched in 2006 for its long journey to the dwarf planet Pluto. It is expected to reach the distant world in 2015.
That’s all for now, folks. Have a great week!
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