The Martian Moons

moons_apparent-sizesThe Curiosity rover on Mars used its cameras to take the series of pictures stitched together to make this video. These are the first images from missions on the surface which have caught one moon eclipsing the other. The images were taken on 1 August, 2013, but some of the full-resolution frames were not downlinked until more than a week later, in the data-transmission queue behind higher-priority images being used for planning the rover’s drives.

The picture on the left shows how big the moons of Mars appear to be, as seen from the surface of Mars, compared to the size that Earth’s moon seen from the surface of Earth.

Image and Video Credits: NASA

A Helicopter on Mars

Nighttime temperatures at Jezero Crater on Mars can drop to -90 C which can damage unprotected electrical components and ruin batteries. However, the Ingenuity helicopter survived its first night after being deployed from the Perseverance rover on 3 April. If all goes well, Ingenuity will be the first aircraft to attempt powered, controlled flight on another planet.

Image Credit: NASA

A Landing Site on Mars

The day after the Perseverance rover landed on Mars, the Mars Reconnaissance Orbiter took this picture of the landing site. The image shows the location of the Mars 2020 mission descent stage, heat shield, and parachute and back shell that delivered Perseverance to the surface of Mars as well as the rover itself on the floor of Jezero Crater. Each the inset box spans is about 200 m across. Perseverance is located at the center of the pattern created by rocket exhaust from the the descent stage while it hovered and lowered the rover to the surface. After lowering the rover, the descent stage itself flew off, crashing a safe distance from the rover. After their separation in the landing sequence, the heat shield, parachute, and back shell fell to their own impact sites.

Image Credit: NASA

Looking at Mars at Night in UV

This obviously false color animation of Mars shows how its atmosphere glows and pulsates in ultraviolet light every night. It was assembled from months of data taken by the MAVEN spacecraft orbiting Mars. The nightglows occur three times during each rotation of the planet about 70 km above the surface. All three occur at sunset (which is on the left limb of the planet in this view). The pulsations are believed to be caused by downward winds creating nitric oxide in the atmosphere which glows in the UV spectrum. The fact that the three glows occur in data averaged over several months indicates that they are a nightly occurrence.

Video Credit: NASA

THEMIS Looks at Phobos

These animations shows three views of the Martian moon Phobos as viewed by the Mars Odyssey orbiter. The apparent motion is due to movement by Odyssey’s camera, Thermal Emission Imaging System (THEMIS) rather than moon.

Each of the three panels is a series of images taken on different dates (from top to bottom): 29 September, 2017; 15 February, 2018; and 24 April, 2019. Deimos, Mars’ other moon, can also be seen in the second panel. These are visible light images, but THEMIS is mainly used for thermal-infrared scans.

Image Credit: NASA

Phobos and Deimos

Mars has two small moons. Phobos, which is about 11.5 km across, was imaged on 26 March, 2019, as in moved across the face of the Sun from Curiosity rover’s post of view. Deimos, which is only about 2.3 km across, was 17 March. Phobos doesn’t completely cover the Sun, so Curiosity saw what could be considered an annular eclipse. Deimos is so small compared to the disk of the Sun, astronomers would say it transited the Sun.

Image Credits: NASA

Bonus GIF—This series of images shows the shadow of Phobos as it sweeps over Curiosity and darkens the sunlight near sunset on 25 March.