The HiRise super-camera locates InSight on the surface of Mars
The exact location of the InSight lander on the surface of the Red Planet has just been determined thanks to the HiRise super-camera on NASA's Mars Reconnaissance Orbiter satellite.
Publication date: 06/12/2018
General public, Observatories, Press, Research
Related observatories : InSight Observatory
Related themes : Earth and Planetary Interiors
The first attempt to immortalise the probe on the surface of Mars, shortly after landing, was inconclusive, as InSight deviated slightly from the centre of the ellipse of uncertainty, an area measuring 130 kilometres long and 27 kilometres wide, within which the spacecraft had a 99% chance of landing.
In anticipation of another pass by Mars Reconnaissance Orbiter, the engineers have been hard at work estimating the approximate position of the lander using various methods. The information provided by the lander’s inertial navigation unit (IMU) has made it possible to define an initial region. The probable area where InSight is located was then narrowed down by analysing the information collected during the landing sequence itself and finally by studying the X-band radio signals emitted by the RISE antennae. At this stage, InSight’s position was still a few hundred metres inaccurate.
For their part, the geologists attempted to link the features visible on the landing site and photographed by the IDC camera on the robotic arm, with HiRise images obtained during numerous previous overflights of the landing site. This was a delicate task, given that the lava plain on which the probe landed was chosen precisely because of its lack of relief. During this search, even the largest rocks on the site were used as landmarks, which gives an idea of the quality of the mapping databases now available for Mars.
However, it was Mars Reconnaissance Orbiter that had the last word, identifying the lander as well as the elements that the probe left behind when it began its descent: the heat shield, which crashed against the rim of an impact crater, as well as the parachute, attached to the rear shield and which no doubt rattles every day in the winds that sweep through the region. These various components are scattered over an area of several hundred metres.
The lander is particularly well visible, thanks to the shadow cast by its two circular solar panels (2.2 metres in diameter) on the ground and the presence of highly reflective structures, such as the WTS, on the deck. Another notable aspect is the presence of a blackened area all around the probe, due to the blast from the retrorockets that scoured the surface during the final phase of the descent and removed a layer of light-coloured dust, which is otherwise omnipresent on Elysium Planitia. The HiRise images showing InSight were obtained on December 6th and 11th 2018.
