And, especially if you're on the southern half of Earth's globe, Venus and Mercury are also back in the evening sky.

Air temperatures in the Arctic are increasing at least twice as fast as the global average due to climate change. What worries climate scientists about this?

What would an extraterrestrial intelligence need to observe Earth, long-term, from nearby? Materials, a firm anchor, concealment? Earth's co-orbital objects, or quasi-satellites, might be the ideal place to "lurk."

Why does Venus' upper atmosphere circle the planet in just 4 Earth-days, while the planet itself takes 243 Earth-days to spin once? Japan's Akatsuki spacecraft probed the mysterious "super-rotation" of Venus' clouds.

Arctic sea ice likely reached its smallest extent for 2019 on September 18. At 1.6 million square miles (4.15 million square km), that minimum is now in a 3-way tie for 2nd-smallest in the satellite record.

As September ends and October begins, you'll find the moon back in the evening sky. Look west shortly after sunset!

For decades, astronomical theorists have told us that a black hole's powerful gravity would warp the space around it. This new visualization from NASA's Goddard Space Flight Center is the best yet at showing exactly how.

Take one minute to watch a video of a system of 3 galaxies - called SDSS J0849+1114 - all orbiting each other a billion light years from Earth. Each galaxy contains a supermassive black hole, which are circling each other, about to collide.

The first known interstellar visitor received the official name 'Oumuamua, meaning 'scout.' This one has a less romantic name and one that sets a standard for future discoveries: 2I/Borisov.

Maps are handy for travel. But what if you're traveling to a place never before visited? For the ExoMars mission, due to launch next summer, scientists have developed new 3-D models of the area to be explored, which may be an old Martian river delta.