In one of the most comprehensive multi-observatory galaxy surveys yet, astronomers find that galaxies like our Milky Way underwent a stellar "baby boom," churning out stars at a prodigious rate, about 30 times faster than today.
Our sun, however, is a late "boomer." The Milky Way's star-birthing frenzy peaked 10 billion years ago, but our sun was late for the party, not forming until roughly 5 billion years ago. By that time the star formation rate in our galaxy had plunged to a trickle.
Our sun is constantly changing. It goes through cycles of activity - swinging between times of relative calm and times when frequent explosions on its surface can fling light, particles and energy out into space. This activity cycle peaks approximately every 11 years. New research shows evidence of a shorter time cycle as well, with activity waxing and waning over the course of about 330 days.
a set of enigmatic quasar ghosts -- ethereal green objects which mark the graves of these objects that flickered to life and then faded. The eight unusual looped structures orbit their host galaxies and glow in a bright and eerie goblin-green hue. They offer new insights into the turbulent pasts of these galaxies.
Three crew members representing the United States and Russia are on their way to the International Space Station after launching from the Baikonur Cosmodrome in Kazakhstan at 3:42 p.m. EDT Friday (1:42 a.m., March 28 in Baikonur).
NASA astronaut Scott Kelly and Russian Federal Space Agency (Roscosmos) cosmonaut Mikhail Kornienko will spend about a year living and working aboard the space station to help scientists better understand how the human body reacts and adapts to the harsh environment of space.[image-51]
The planet Mercury’s puzzlingly dark color could result from its bombardment with carbon-rich micrometeorites, reports a study in Nature Geoscience. This may explain why the Moon is lighter in color than Mercury, even though the Moon’s surface contains more darkening iron.
Observations of Mercury reveal a planet that reflects little light and also has a low surface iron content, suggesting that another material is probably responsible for its observed dark surface. Comets are rich sources of carbon and they more frequently impact planets closer to the Sun.
A new analysis of an ancient Martian lake system in Jezero Crater, near the planet's equator, finds that the onslaught of water that filled the crater was one of at least two separate periods of water activity in the region surrounding Jezero.
On Earth, bursts of particles spewed by the Sun spark shimmering auroras, like the Northern Lights, that briefly dance at our planet's poles. But, on Jupiter, there's an auroral glow all the time, and new observations show that this Jovian display sometimes flares up because of a process having nothing to do with the Sun.
Long before Mercury, Venus, Earth, and Mars formed, it seems that the inner solar system may have harbored a number of super-Earths--planets larger than Earth but smaller than Neptune. If so, those planets are long gone--broken up and fallen into the sun billions of years ago largely due to a great inward-and-then-outward journey that Jupiter made early in the solar system's history.
The past week saw a fantastic treat for aurora watchers. Generally it is the southern part of the country, Tasmania in particular, that sees the most impressive displays. But this aurora has been so intense that it was even seen across New South Wales and up around Brisbane it added a red glow to the sky.
Sifting through the center of the Milky Way galaxy, astronomers have made the first direct observations - using an infrared telescope aboard a modified Boeing 747 - of cosmic building-block dust resulting from an ancient supernova.
Scientists have produced a new map of the Moon's most unusual volcano showing that its explosive eruption spread debris over an area much greater than previously thought. The team of astronomers and geologists, studied an area of the lunar surface in the Compton-Belkovich Volcanic Complex.
By mapping the radioactive element thorium which spewed out during the eruption they discovered that, with the help of the Moon's low gravity, debris from the unnamed volcano was able to cover an area the size of Scotland, or around 70,000 km2.
Astronomers have discovered thousands of exoplanets in our galaxy, the Milky Way, using the Kepler satellite and many of them have multiple planets orbiting the host star. By analysing these planetary systems, researchers from the Australian National University and the Niels Bohr Institute in Copenhagen have calculated the probability for the number of stars in the Milky Way that might have planets in the habitable zone.
ASA's Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter's largest moon. The subterranean ocean is thought to have more water than all the water on Earth's surface.
Identifying liquid water is crucial in the search for habitable worlds beyond Earth and for the search of life as we know it.
Azotosome. Credit: Cornell University
A new type of methane-based, oxygen-free life form that can metabolize and reproduce similar to life on Earth has been modeled by a team of Cornell University researchers.
Enormous cloud-like plumes reaching 260km above the surface of Mars have left scientists baffled. This is way beyond Mars’s normal weather, reaching into the exosphere where the atmosphere merges with interplanetary space. None of the conventional explanations for such clouds make sense – neither water or carbon dioxide ice nor dust storms nor auroral light emissions usually hit such heights.