https://www.cnet.com/news/after-nasa-insight-mars-landing-what-happens-next/

Later on Monday, NASA received confirmation that the solar arrays are in place and working. This will be critical to ensuring InSight can actually carry out its mission to explore the interior of Mars, listen for "Marsquakes" and figure out how many meteorites batter the Red Planet. 

"We are solar powered, so getting the arrays out and operating is a big deal," InSight project manager Tom Hoffman said in a statement following the landing. "With the arrays providing the energy we need to start the cool science operations, we are well on our way to thoroughly investigate what's inside of Mars for the very first time."