Showing posts from August, 2020

How Do You Solve a Moon Mystery? Fire a Laser at It Source:    By Katherine Kornei, The New York Times.  Excerpt: The moon is drifting away. Every year, it gets about an inch and a half farther from us. Hundreds of millions of years from now, our companion in the sky will be distant enough that there will be no more total solar eclipses. For decades, scientists have measured the moon’s retreat by firing a laser at light-reflecting panels, known as retroreflectors, that were left on the lunar surface, and then timing the light’s round trip. But the moon’s five retroreflectors are old, and they’re now much less efficient at flinging back light. To determine whether a layer of moon dust might be the culprit, researchers devised an audacious plan: They bounced laser light off a much smaller but newer retroreflector mounted aboard a NASA spacecraft that was skimming over the moon’s surface at thousands of miles per hour. And it worked. These results were published this month

Extremely young galaxy is Milky Way look-alike Source:   By Science Daily. Excerpt: Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, have revealed an extremely distant and therefore very young galaxy that looks surprisingly like our Milky Way. The galaxy is so far away its light has taken more than 12 billion years to reach us: we see it as it was when the Universe was just 1.4 billion years old. It is also surprisingly unchaotic, contradicting theories that all galaxies in the early Universe were turbulent and unstable. This unexpected discovery challenges our understanding of how galaxies form, giving new insights into the past of our Universe. "This result represents a breakthrough in the field of galaxy formation, showing that the structures that we observe in nearby spiral galaxies and in our Milky Way were already in place 12 billion years ago," says Francesca Rizz

This is the way the universe ends: not with a whimper, but a bang. Source:   By Adam Mann, Science Magazine.  Excerpt: In the unimaginably far future, cold stellar remnants known as black dwarfs will begin to explode in a spectacular series of supernovae, providing the final fireworks of all time. That’s the conclusion of a new study, which posits that the universe will experience one last hurrah before everything goes dark forever. ...The known laws of physics suggest that by about 10 100  (the No. 1 followed by 100 zeros) years from now, star birth will cease, galaxies will go dark, and even black holes will evaporate through a process known as Hawking radiation, leaving little more than simple subatomic particles and energy. The expansion of space will cool that energy nearly to 0 kelvin, or absolute zero, signaling the heat death of the universe and total entropy. ...The particles in a white dwarf stay locked in a crystalline lattice that radiates heat for trillions of ye

Planet Ceres is an 'ocean world' with sea water beneath surface, mission finds Source:  By The Guardian.  Excerpt: Dwarf planet, believed to be a barren space rock, has an ‘extensive reservoir’ of brine beneath its surface, images show. The dwarf planet Ceres – long believed to be a barren space rock – is an ocean world with reservoirs of sea water beneath its surface, the results of a major exploration mission showed on Monday. Ceres is the largest object in the asteroid belt between Mars and Jupiter and has its own gravity, enabling the Nasa Dawn spacecraft to capture high-resolution images of its surface. Now a team of scientists from the United States and Europe have analysed images relayed from the orbiter, captured about 35km (22 miles) from the asteroid. They focused on the 20-million-year-old Occator crater and determined that there is an “extensive reservoir” of brine beneath its surface....  See also article Dwarf planet Ceres is an ocean world with salt