Searching for Signs of Life on Mars.
Last fall, the GRPM published a blog post about the Mars opposition. Opposition is the closest approach between Earth and Mars as they make their respective orbits around the Sun. It happens about every 26 months and is also the ideal time to launch a spacecraft to Mars. During the last opposition, NASA launched Mars 2020; this is the first NASA mission with the specific goal of studying past habitability of the planet.
The mission’s expected landing date of Thursday, February 18 is approaching quickly. After 7 months and 300 million miles, this is the perfect time to explore this mission in more detail and find out how you can watch the Mars landing!
Perseverance and Ingenuity at Mars.
The new Mars rover, called Perseverance, is built on the same six-wheel design as the Curiosity rover. What makes Perseverance unique is the new array of science instruments that focus on astrobiology. These instruments include 23 cameras and microphones, as well as radar to search for minerals just below the Martian surface. A spectrometer called SHERLOC will search for organic compounds. Perseverance is also fitted with a drilling system to collect samples and seal them in air-tight containers that a future spacecraft can collect and return to Earth. However, Perseverance is quite capable of studying the samples on its own, too. The Mars rover is a rolling science laboratory slightly smaller than a compact car.
Another experiment, called MOXIE, will attempt to produce oxygen from the carbon dioxide Martian atmosphere. In principle, a scaled-up version of this experiment could produce breathable air for human astronauts.
The mission also includes a technology demonstration of the Ingenuity Mars Helicopter. Ingenuity is a small helicopter drone that will attempt the first flight on another planet. Ingenuity can help Perseverance map out the Martian surface and find the best path to travel.
Was There Life on Mars?
There is no hard evidence of past or present life on Mars, but it is still a good place to search for life because it had conditions similar to the Earth’s, approximately 3-4 billion years ago. Also, because Mars lacks plate tectonics, parts of its surface remain relatively unchanged since that time period. If there was life, it is possible evidence remains very close to the surface. In the distant past, Mars had oceans of liquid water and a carbon dioxide atmosphere. Martian ground features from this time period show abundant evidence of liquid water including erosion, drainage basins and river deltas.
On February 18, Perseverance will land on Jezero Crater, a 45 km-wide basin that was once a lake filled with water. It is an ideal place to search for evidence of Martian life, although it is very unlikely that Perseverance would find any microorganisms currently living on Mars. While there is evidence that Mars may have been habitable in the past, it certainly does not have Earth-like conditions today. For starters, there is no magnetosphere. The Earth’s spinning iron-nickel core creates a magnetic force field. This magnetic field protects Earth’s life from most of the Sun’s deadly radiation. Mars has further problems which stem from this lack of a magnetosphere; without a magnetosphere, Mars’ atmosphere and water vapor was blown away by solar radiation over the course of a couple billion years. Today, the Martian atmosphere is less than 1% of the pressure of Earth’s atmosphere. That is too thin for liquid water on the surface. If an astronaut visitor were to open a water bottle on Mars, it would instantly boil away due to the vacuum. Today, Martian water exists as ice on the north and south poles, and small amounts underground.
In 2018, the satellite Mars Express reported a subglacial lake of liquid water on the south pole of Mars. This stable body of water was under the glacial ice. It is probably very salty, otherwise it would not be able to stay liquid in the -110°C Martian winters. If there is liquid water, there is a small chance microorganisms could still live in this underground refuge.
The search continues!
Where to Watch the Perseverance Landing.
The Perseverance landing will be live streamed by NASA TV on February 18, starting at 2:15 EST.
By: Jack Daleske, the GRPM’s Planetarium Manager