Joe Palka

But even if it were circular, there would still be seasons.

That's because the Earth is tilted away from straight up and down in its orbit.

The tilt is significant, 23 degrees.

In winter, the North Pole points away from the sun, and in summer, towards the sun.

Longer time bathed in sunlight does more to explain changes in temperature than slight changes in distance.

For NPR News, I'm Joe Palka.

The excitement came from an opportunity to take images of an object with the prosaic name 3I Atlas.

Astronomers spotted 3I Atlas last summer and determined it was a comet.

Its speed and trajectory have convinced them it came from a distant star.

This is only the third such interstellar visitor to be detected near Earth.

In September, Psyche's mission managers scrambled to orient the probe so it could catch a glimpse of 3I Atlas, helping to refine its trajectory through our solar system.

Psyche's main mission is to visit an asteroid made primarily of metals, possibly providing clues about how Earth's metal core formed.

The probe will reach its target in 2030.

For NPR News, I'm Joe Palka.

There was no indication MAVEN was having any technical problems earlier this month when its orbit took it behind Mars, out of sight from Earth-based antennas.

But when it came back into view, no signal came from the probe's radio.

Tracking data suggested the spacecraft might be rotating and that its orbit might have changed, but there was no apparent reason why.

NASA has tried to use the camera on the rover Curiosity to capture a picture of the orbiter from the Martian surface, but so far, no luck.

Future rescue efforts face an orbital problem.

Starting December 29th, the Sun will be between the Earth and Mars, making communication between the two planets impossible for about three weeks.