When Comet Leonard, a mass of space dust, rock and ice about a half-mile (1 kilometer) wide, makes its closest pass of the Sun on Jan. 3, 2022, it will be a journey 40,000 years in the making. Ahead of its close pass, two Sun-observing spacecraft captured these views of the comet.

The animated image at right was captured by NASA's Solar Terrestrial Relations Observatory-A spacecraft, SECCHI/HI-2 telescope, which has watched the comet since early November. This animated "difference image" was created by subtracting the current frame from the previous frame to highlight differences between them. Difference images are useful for seeing subtle changes in Leonard's ion tail (the trail of ionized gases streaming from the comet's body, or nucleus), which becomes longer and brighter toward the end of the clip.

The video below, captured between Dec. 17-19, 2021 by the Solar Orbiter Heliospheric Imager (SoloHI) aboard the ESA/NASA Solar Orbiter spacecraft, shows Comet Leonard streaking diagonally across the field of view with the Milky Way in the background. Venus and Mercury are also visible in the top right, Venus appearing brighter and moving from left to right.

Aerospace engineers at MIT are testing a new concept for a hovering rover that levitates by harnessing the moon's natural charge.

Because they lack an atmosphere, the moon and other airless bodies such as asteroids can build up an electric field through direct exposure to the sun and surrounding plasma. On the moon, this surface charge is strong enough to levitate dust more than 1 meter above the ground, much the way static electricity can cause a person's hair to stand on end.

Engineers at NASA and elsewhere have recently proposed harnessing this natural surface charge to levitate a glider with wings made of Mylar, a material that naturally holds the same charge as surfaces on airless bodies.