Spinning Ceres

Dawn20150219Ceres rotates in this sped-up movie assembled from images taken by the Dawn spacecraft as is neared the dwarf planet on 19 February. The images were taken at a distance of about 46,000 km. A full rotation of Ceres takes around nine hours.

Dawn should enter orbit around Ceres on Friday.

Image Credit: NASA

Dawn Approaches Ceres

Dawn20150219This image of Ceres was taken by the Dawn spacecraft on 19 February from a distance of around(46,000 km). As the probe has drawn closer to the dwarf planet, we’ve been seeing bright spots on the surface. This picture shows that the brightest spot on Ceres has a dimmer companion which seems lies in the same basin. More will be revealed soon. Dawn will enter orbit around Ceres in a few days.

Image Credit: NASA

Beyond Pluto

KBO1110113Y1110113Y (aka PT1) is Kuiper Belt Object (KBO) that is potentially reachable as a additional flyby target for the Pluto-bound New Horizons spacecraft. It is visible in this image taken with the Hubble Space Telescope. Hubble tracked the KBO moving against the star field in the constellation Sagittarius. The object is small, no bigger than 19 to 28 miles across, and it is a relic of the outer solar system from billions years ago, during the period when the Sun formed. As the KBO orbits the Sun, its position noticeably shifts between exposures taken approximately 10 minutes apart, resulting in the diagonal string of equally spaced dots near the center of the picture. This KBO has been identified as “definitely reachable” by New Horizons.

Image Credit: NASA

Star Dust

BetaPictorisDustThus far, Beta Pictoris is the only star which astronomers have detected a giant planet orbiting in a directly-imaged debris disk. The planet, which was discovered at the European Souther Observatory in 2009, goes around the star once every 18 to 20 years. It is being watch to see how a large planet distorts the massive gas and dust encircling the star. These observations should yield new information about how planets are born around young stars. Beta Pictoris is only about 20 million years old.

The images above were taken with Hubble’s Space Telescope Imaging Spectrograph in its coronagraphic imaging mode.  The coronagraph blocks out the glare of the central star so that the disk can be seen. The visible-light images trace the disk to within about 650 million miles of the star. The giant planet orbits at around 900 million miles.

Comparison of the 1997 and 2012 images shows that the distribution of the dust has not changed much over 15 years despite the fact that the entire structure is moving in orbit the star. This implies that the disk’s structure has been smooth and continuous, at least over the period between the Hubble observations.

One more thing … The Beta Pictoris disk is exceptionally dusty. That may have been caused by recent major collisions among unseen planet and asteroid-sized objects in the disk. One bright glob of dust and gas could be the result of the pulverization of a Mars-sized object in a giant collision. (Marvin was unavailable for comment.)

Image Credit: NASA / ESA