After a treacherous journey, NASA’s Curiosity Mars rover has reached an area that is thought to have formed billions of years ago when the Red Planet’s water disappeared.
Lying part-way up the slopes of “Mount Sharp”, the mound of material deposited at the centre of Gale Crater (and formally called Aeolis Mons), is rich in salty minerals scientists think were left behind when the streams and ponds on the slopes of the mound finally dried up. As such, this region could hold tantalizing clues about how the Martian climate changed from being similar to Earth’s to the frozen, barren desert we know today.
These salty minerals were first spotted from orbit by NASA’s Mars Reconnaissance Orbiter before Curiosity arrived on Mars in 2012, and that discovery marked the deposits as a prime target for the rover to examine. However, such is the rich diversity of rocks and minerals making up “Mount Sharp”, all of which have been subject to examination by the rover, it has taken the mission almost a decade to reach this “prime” target.
Even so, before Curiosity could obtain any samples from the site, the rover faced a couple of challenges.
The first lay in the fact that the rover’s position on “Mount Sharp” meant that the mission team had to drive and position the rover to ensure its antenna could remain aligned with the various orbiters it needs to use to communicate with Earth; this made navigating to the deposits a challenge, as has ensuring it can reach rocks that might yield interesting samples.
The second required further tests had to be carried out on the rover’s sample-gathering drill to ensure it would handle the stresses in cutting into the region’s rocks. As designed, the drill was intended to use a percussive action as it drilled into any target- but as I’ve reported in these pages, this hammering action started to affect the drilling mechanism as a whole, so a new algorithm was created and uploaded to the rover to minimise any use of the percussive action.
Because of this, the mission team now approach each sample gathering operation with an additional step: after scouring the surface of a sample rock to remove dust and debris, the team then position the drill bit against the rock and attempt to scratch the surface – any resultant marks would be a good indication the rock is soft enough to be drilled without the need for the hammer option.
In the case of this rock – nicknamed “Canaima” – no marks were left, indicating it might prove a difficult subject. However, a further test with the drill head turning revealed it could cut the rock without the use of the hammer action, so on October 3rd, 2022, Curiosity successfully obtained its 36th sample for on-board analysis.
The route to this sulphate-rich area also required Curiosity pass through a narrow, sand-rich location dubbed “Paraitepuy Pass”, bordered on either side by slopes the rover could not drive over or along. Such is the nature of the sand the rover took over a month to traverse the pass, moving cautiously in order to avoid getting bogged-down. This meant that the rover celebrated its 10th anniversary crossing the pass.
The challenges also haven’t ended; the salty region comprises rocky terrain that is so uneven, it will be difficult for Curiosity to place all six wheels on stable ground. This isn’t a problem when on the move, but it could limit science operations in the area: if all of the rovers wheels are not in firm contact with the ground under them, operators won’t risk unfolding its instruments-loaded robot arm in case it clashes with jagged rocks.
Even so, the rover still has a lot of opportunities for science and discovery as it continues to climb “Mount Sharp”.
JWST Wows, HST, Chandra and IXPE Respond
It is now 100 days since the James Webb Space Telescope commenced operations, and in their most recent updates, NASA released a stunning image the observatory captured of the iconic Pillars of Creation.
Located in the Serpens constellation, roughly 6,500-7,000 light-years from Earth, the Pillars are gigantic “elephant trunks” of interstellar gas and dust, a birthplace of new stars, constantly, if slowly being changed by the very stars born within them. They were imaged by the Hubble Space Telescope (HST) in 1995, the image becoming famous the world-over despite HST imaging them again it 2014. However, the image developed by JWST’s Near Infra-red Camera (NIRCam) eclipses the Hubble image, revealing the pillars and their surroundings in incredible detail.
Newly formed stars lie outside of the column. Seen merely as a few bright red orbs with strong diffraction spikes radiating from them, they are reveal by JWST as in their truer colours – blues, yellows, whites, indicative of their spectral classes, a veritable sea of stars, These are the stars that are causing the pillars to change and collapse as a mix of their gravities and radiative energy influence their form.
Also visible along the edge of the pillars are wavy forms, the ejections of gas and dust from stars that are still forming. The crimson glow seen within some of these wave-like forms is the result of energetic hydrogen molecules interacting with the supersonic outbursts of the still-forming stars. Within the cloudy forms of the pillar are red points of light – newly-formed stars that are just a few hundred thousand years old, the light just stars to break through the surrounding clouds of dust and material.
Around all of this is a translucent blue glow, a mix of dust and gas known as the interstellar medium, found in the densest part of our galaxy’s disk. It serves to block the view of the deeper universe, bringing the Pillars of Creation to the fore.
This new view of the Pillars will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.