This is the second-largest asteroid in the main belt between Jupiter and Mars. Surprisingly, such an important object still could not be explored in the vicinity. NASA is going to fix it with a new mission.
Asteroid Pallada
Pallas asteroid in the eyes of an artist
For the first time this object was noticed by Charles Messier in 1779. He recorded it next to the comet Bode’s route, and considered that there was a star in front of him. In 1802, astronomer Heinrich Olbers finds Pallada as an asteroid, and as a result, the object becomes the second asteroid discovered.
Due to lack of data, disputes about primacy in size and mass began. First, it was considered that Ceres was in the first place among the asteroids, then Pallas followed, and only then Vesta. After the events with Pluto shifting into the ranks of dwarf planets, Ceres followed him. It was also possible to carefully examine the size of Vesta and Pallas and it turned out that Pallas is inferior.
However, it is still a large 512 km (+/- 6 km) space object that is worth exploring. The fact is that many see it as a kind of intermediate stage between the dwarf planet Ceres and the largest asteroid, Vesta. They are called failed planets or protoplanets, so a careful examination of Pallas will help answer many questions.
Future mission
Comparative sizes of four largest asteroids
Since this is a huge and unexplored asteroid, they decided to send a mission to it, which can start as early as 2022. As an option, consider launching a spacecraft, called Athens. In size it will resemble a small refrigerator with a weight of 181 kg and a large carrying capacity to transport the necessary set of appliances.
The project refers to the programs of small satellites SmallSat and CubeSat. The problem is that 11 more scientific proposals compete for the possibility of sending into space. Therefore, in April, NASA representatives should decide on the choice of mission.
The object is maximally removed from the Sun by 3.4 a. e., however, the path to it will be difficult. Engineers will have to work over the trajectory, since the Pallas orbit is inclined by 34.8 ° to the plane of the asteroid belt (they believe that it is all about a collision with a large asteroid). And the eccentricity is almost the same as that of Pluto. That is, it is very difficult to get to this asteroid.
Comparative sizes of Pallas and the Moon
If this project is chosen, the satellite will be launched in tandem with a spacecraft directed to Psyche asteroid. The flight will take about two years. Some researchers believe that this world is fraught with many interesting features. Do not exclude volcanic and geological activity.
Interesting Facts
- The name was given in honor of the daughter of Triton and the sister of Athena Pallas.
- Because of its large size, an asteroid is formally sometimes called a dwarf planet, but the shape did not reach the ellipsoid.
- Pallas by mass takes 7% of the total massiveness of the asteroid belt.
- There is a suspicion that in front of us is not an asteroid, but the remnants of a protoplanet (it will only be possible to find out with the dispatch of a spacecraft).
- Spectroscopic analysis revealed the presence of silicates with small admixtures of water and iron on the surface.
Postscript
All information indicates that the asteroid Pallas appeared in an environment with an abundance of water. Therefore, the scientific objectives of the ship Athens will include determining whether the asteroid is able to have a rich aquatic mantle and crust.
