Vesta Full Frame

Vesta
Vesta Image from 5,200 kilometers
Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
See also full rotation movie of Vesta.

The Dawn spacecraft has completed imaging of Vesta from an altitude of 5,200 kilometers and has begun spiraling down to an altitude of 2,700 kilometers for the first series of scientific observations.

Chris Russell, Dawn’s principal investigator at UCLA, notes:

We have been calling Vesta the smallest terrestrial planet. The latest imagery provides much justification for our expectations. They show that a variety of processes were once at work on the surface of Vesta and provide extensive evidence for Vesta’s planetary aspirations.

Below are additional images of Vesta from the 24 July collection.

Vesta
The “Snowman” on Vesta
Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
Vesta
The Southern Hemisphere of Vesta with a multitude of craters
Image Credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA

Is an Earth Trojan Asteroid the Logical Target for the "Flexible Path"?

Trojan Asteroid 2010 TK7
Asteroid 2010 TK7 is circled in green.
Image Credit: NASA / JPL-Caltech / UCLA
Scientists using the Wide-field Infrared Survey Explorer (WISE) have discovered the first Trojan Asteroid in Earth orbit. Trojans orbit at a location in front of or behind a planet known as a Lagrange Point.

A video of the asteroid and its orbit at the Lagrange point can be found here.

Martin Connors of Athabasca University in Canada is the lead author of a new paper on the discovery in the July 28 issue of the journal Nature.

Connors notes that:

These asteroids dwell mostly in the daylight, making them very hard to see. But we finally found one, because the object has an unusual orbit that takes it farther away from the sun than what is typical for Trojans. WISE was a game-changer, giving us a point of view difficult to have at Earth’s surface.

TK7 is roughly 300 meters in diameter and traces a complex motion around SEL-4 (Sun Earth Lagrange point 4). The asteroid’s orbit is stable for at least the next 100 years and is currently about 80 million kilometers from the Earth. In that time, it is expected to come no closer that 24 million kilometers.

The obvious question is whether this is the logical destination for NASA’s Flexible Path manned asteroid mission? The Lagrange 4 point (SEL-4) is a logical way station on the Solar System exploration highway. Other NEO asteroids that have been identified as possible targets are few and much more difficult to reach and return than an asteroid located directly at SEL-4 would be. An asteroid located there could well be the target of opportunity that opens manned exploration of the Solar System in an “easy” mode. Unfortunately, Asteroid 2010 TK7 would not serve as such a target because it travels in an eccentric orbit around SEL-4 so far above and below the plane of Earth’s orbit that it would require very large amounts of fuel to reach.

NEOWISE is the program for searching the WISE database for Near Earth Objects (NEO), as well as other asteroids in the Solar System.The NEOWISE project observed more than 155,000 asteroids in the main belt between Mars and Jupiter, and more than 500 NEOs, discovering 132 that were previously unknown.