Category Astronomy/Space

A new paper uses laboratory simulations of an Earth impact as evidence that a stratified layer beneath the rocky mantle — which appears in seismic data — was created when the Earth was struck by a smaller object. The authors argue this was the same impact that sent a great mass of debris hurtling into space, creating the moon. Credit: © Gudellaphoto / Fotolia

A layer of iron and other elements deep underground is the evidence scientists have long been seeking to support the hypothesis that the moon was formed by a planetary object hitting the infant Earth some 4.5 billion years ago, a new study led by Johns Hopkins University scientists argues...

Milky Way (stock image). A team of researchers has developed a new experimental Meteoric Ablation Simulator (MASI) that can help answer questions about cosmic dust and how it impacts Earth and everything on it. Credit: © sripfoto / Fotolia

University of Leeds team has developed a new experimental Meteoric Ablation Simulator (MASI) that can help answer questions about cosmic dust and how it impacts Earth and everything on it. The study of the evaporation of cosmic dust particles in the upper atmosphere has, until now, relied heavily on theoretical calculations. Evidence provided by field radar and optical observations of meteoroids is contradictory in relation to the height where each of the metals in the particles will ablate as they fall through the atmosphere...

This composite image shows suspected plumes of water vapor erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The plumes, photographed by NASA’s Hubble’s Space Telescope Imaging Spectrograph, were seen in silhouette as the moon passed in front of Jupiter. Hubble’s ultraviolet sensitivity allowed for the features — rising over 100 miles (160 kilometers) above Europa’s icy surface — to be discerned. The water is believed to come from a subsurface ocean on Europa. The Hubble data were taken on January 26, 2014. The image of Europa, superimposed on the Hubble data, is assembled from data from the Galileo and Voyager missions. Credit: NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center

This finding bolsters other Hubble observations suggesting the icy moon erupts ...

Artist’s conception. Credit: courtesy of Robin Dienel

When a star is young, it is often still surrounded by a primordial rotating disk of gas and dust, from which planets can form. Astronomers like to find such disks because they might be able to catch the star partway through the planet formation process, but it’s highly unusual to find such disks around brown dwarfs or stars with very low masses. New work from a team led by Anne Boucher of Université de Montréal, and including Carnegie’s Jonathan Gagné and Jacqueline Faherty, has discovered 4 new low-mass objects surrounded by disks.

3 of 4 objects discovered by these researchers are quite small, somewhere between only 13 and 18 times the mass of Jupiter. The fourth has about 120 times Jupiter’s mass...