NASA’s latest Mars lander has a very precise weather package, and you can check the daily conditions on Elysium Planitia online. The data however has apparently led to a bit of a mystery. According to Ars Technica, every day at 7AM and 7PM local time, there’s an unexplained atmospheric pressure spike.

The TWINS (Temperature and Wind for InSight) package provided by Spain’s Centro de Astrobiología shows the little spikes regularly since the lander hit the ground in November. They seem to correspond to local sunrise and sunset. Keep in mind, the pressure on Mars is very low — about 1% of Earth’s atmosphere — and scientists have already ruled out instrument problems.

The technical side of TWINS includes thermometers, as well as an anemometer to measure wind speed and direction twice per second. Additional sensors include the InSight FluxGate (IFG) magnetometer provided by UCLA to measure the direction and magnitude of magnetic fields; and a highly sensitive barometer from JPL. The sensors have picked up a few mysteries including an unexplained “infrasound.” You can read more about the weather station on NASA’s website.

Proving that social media is everywhere, the lander has its own Twitter account and posts little selfies and tidbits about its day. If you want to hear what the lander hears, you might enjoy the NASA telecon recorded in the video below.

We looked at InSight last year in some detail. Before you start planning your next vacation to Elysium Planitia, you might want to read this.