Insight Lander Detects Third Major Marsquake
It’s been a fun summer for NASA’s InSight lander. Earlier in the season, the lander used scoops of Martian soil to “wash” dust off its solar panels, giving it a much-needed boost in operating power. And it came not a moment too soon. September 18th was a milestone — InSight’s 1000th sol on Mars — and it celebrated by measuring one of the most powerful and longest-lasting Marsquakes the lander has ever recorded. According to NASA, the temblor is estimated to be about a magnitude 4.2, and the earthquake lasted for almost an hour and a half.
It came on the heels of two other major quakes that InSight detected within the same day on Aug. 25, of magnitude 4.2 and 4.1. One of the quakes was “Earth-like” and one of them was “Moon-like,” which is exactly the kind of data we hoped to get because it teaches us more about the internal structure of Mars. Insight listens for earthquakes because we are trying to learn more about how rocky planets form.
“If we hadn’t acted quickly earlier this year, we might have missed out on some great science,” said InSight’s principal investigator, Bruce Banerdt. “Even after more than two years, Mars seems to have given us something new with these two quakes, which have unique characteristics.”
Mission scientists haven’t finished the analysis of this most recent quake, but one thing we do know is that it came from too far away to be from Cerberus Fossae, the source of most of the seismic activity that InSight records.
InSight is on Mars to gather data on seismic and atmospheric activity, with the ultimate goal of learning more about how planets are formed by studying how seismic waves move through the core of Mars. Summer is coming to the planet’s northern hemisphere, and that’s great news for InSight because the winds calm down. Spring is dust season on Mars, which is why the lander had to clean off its solar panels in the first place. In summer, the atmosphere becomes less dense and the wind can’t carry as much dust.
The changing seasons are a big deal for the rovers and landers we have on Mars. Dust and wind are major obstacles for InSight’s seismic readings because wind noise is enough to throw off its sensitive seismometers. The lander was designed with a domed wind shield, to help out with the noise, but dust storms on Mars mean business. They can encircle the entire planet. Worse, they can cover the solar panels with dust and starve the lander of power, which means we can’t use the instruments. And we can’t just ping Ingenuity to come over and blow off the dust: Perseverance and Ingenuity are around 1,500 miles away.
Even the change from day to night has its consequences for InSight. The temperature can swing from almost “minus 148 degrees Fahrenheit (minus 100 degrees Celsius) at night to 32 degrees Fahrenheit (0 degrees Celsius).” These wild swings in temperature can cause the lander’s body and wiring to make clicking and popping sounds as they adjust. It’s the same thing that happens when the TV or monitor make little clicking noises as they’re cooling down after you turn them off.
It’s important to have InSight in the best condition possible because we’re about to lose contact. Mars’ solar conjunction is approaching, when Earth and Mars are on opposite sides of the Sun. Having the sun exactly in the middle scrogs up the radio signals and interferes with communication, so InSight’s team will stop issuing commands to the lander on Sept. 29. But don’t worry: InSight will still be listening.