There Might Be Water on the Surface of the Metal Asteroid Psyche

While a NASA probe heads for an asteroid known as Psyche, telescopes have been probing it to prepare for the arrival. Data from the James Webb Space Telescope has found something quite unexpected on the surface – hydrated molecules and maybe even water! The origin of the water is cause for much speculation, maybe it came from under the surface or from chemical interactions with the solar wind! 

Asteroid Psyche was discovered in 1852 by the Italian astronomer Annibale de Gasparis. It was named after the Greek goddess of the soul who was born mortal and married Eros. It measures 225 km across and is one of the most massive objects in the asteroid belt between Mars and Jupiter. Most of the asteroids in the belt are composed of rock and ice but Psyche seems to be different being largely composed of metals, perhaps the exposed core of a protoplanet that lost its outer layers. Psyche is of immense interest to study because it provides an opportunity to study planetary cores which are usually inaccessible. 

Aptly named Psyche, the probe launched by NASA has already started its 3.5 billion km journey to the asteroid, due to arrive in August 2029. With its solar panels deployed, the probe measures 25 metres by 7.3 metres, about the size of a tennis court. It has a mass of 2,747 kg and is powered by five solar panel arrays. Once arrived at Psyche they can generate about 3 kilowatts of power.

While the probe is enroute, telescopes on Earth and in space have been exploring Psyche. Observations in different wavelengths of light have provided information that will aid and support the data collected by the Psyche spacecraft. The study was led by Dr. Stephanie Jarmak from the Southwest Research Institute and it was their observations that confirmed the hydroxyl molecules on the surface. 

The data, which was collected using the James Webb Space Telescope revealed the telltale signs of hydroxyl but stopped short of explaining where they came from. There are two possible explanations and we can look to the origin of asteroids to understand them. They are the leftovers from the formation of planets and their make up is determined by the location in the solar nebula from which they formed. If the hydroxyl formed locally without interference from external process then it might suggest that Psyche is not a planetary core remnant.  It might be that Psyche simply formed at a distance that volatile compounds like water condense to form solids like ice before migrating. 

An alternative model explains the variability of the molecule distribution across the surface. This might indicate that impacts from carbonaceous chondrites (like the meteorites often found on Earth) could have provided the water molecules that have been observed. 

It seems that for now, we will have to wait until the arrival of the Psyche spacecraft in 2029 to unravel the mystery. If we can get a better understanding of the origin of the asteroid Psyche it will help us to learn more about the distribution of elements in the nebula that the planets formed from. In particular, understanding more about the distribution of water will help us to develop a better insight to the origins of life. 

Source : SwRI-Ked Team Finds Evidence of Hydration on Psyche