Astronomy Now – Page 190

Looking for artificial radio signals from star system KIC 8462852

6 November 2015 Astronomy Now

Could there be intelligent life in the star system KIC 8462852? A recent analysis of data collected by NASA’s Kepler space telescope has shown that this star — informally known as Tabby’s Star — displays large, irregular changes in brightness consistent with many small masses orbiting the star in “tight formation”. The SETI Institute trained its Allen Telescope Array on this star for more than two weeks in order to investigate the possibility of a deliberate cause of KIC 8462852’s unusual behaviour.

MAVEN reveals speed of solar wind stripping Martian atmosphere

6 November 2015 Astronomy Now

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has identified the process that appears to have played a key role in the transition of the Martian climate from an early, warm and wet environment that might have supported surface life to the cold, arid planet Mars is today. Researchers have determined the rate at which the Martian atmosphere is losing gas to space via stripping by the solar wind and that the erosion increases significantly during solar storms.

Martian valleys could have been carved by surprisingly little water

5 November 2015 Astronomy Now

Vast valley networks on Mars have suggested that water may have flowed there for millions of years. Now a study at Brown University suggests the valleys could have been carved by much less water in as little as a few hundred to 10,000 years. The findings are consistent with the idea that early Mars may have been cold and icy, with surface water flowing sporadically in response to short-term climate changes.

ALMA observes growing pains in a cluster of protostars

5 November 2015 Astronomy Now

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered an adolescent protostar that is undergoing a rapid-fire succession of growth spurts. Evidence for this fitful youth is seen in a pair of intermittent jets streaming away from the star’s poles. Known as CARMA-7, the protostar is one of dozens of similar objects in the Serpens South star cluster, which is located approximately 1,400 light-years from Earth.

Radar images provide new details on Halloween asteroid

4 November 2015 Astronomy Now

The highest-resolution radar images of 600 metre-wide asteroid 2015 TB₁₄₅‘s safe flyby of Earth have been processed. NASA scientists used giant, Earth-based radio telescopes to bounce radar signals off the asteroid as it flew past Earth on 31 October at 17:00 UTC (~5pm GMT) at about 1.3 lunar distances (302,500 miles, or 486,800 kilometres) from Earth.

Distant world’s weather is mixed bag of hot dust and molten rain

4 November 2015 Astronomy Now

A team led by the University of Edinburgh used a telescope in Chile to study weather systems in the distant world known as PSO J318.5-22 which is estimated to be around 20 million years old. Layers of clouds, made up of hot dust and droplets of molten iron, have been detected on the planet-like object found 75 light-years from Earth, researchers say.

Whopping galaxy cluster spotted with help of NASA telescopes

3 November 2015 Astronomy Now

Astronomers have discovered a giant gathering of galaxies in a very remote part of the universe, thanks to NASA’s Spitzer Space Telescope and Wide-field Infrared Survey Explorer (WISE). The galaxy cluster, located 8.5 billion light-years away, is the most massive structure yet found at such great distances.

Jupiter kicked a giant planet out of the solar system 4 billion years ago

3 November 2015 Astronomy Now

The existence of a fifth giant gas planet at the time of the solar system’s formation — in addition to Jupiter, Saturn, Uranus and Neptune that we know of today — was first proposed in 2011. Now astrophysicists at the University of Toronto have found that a close encounter with Jupiter about four billion years ago may have resulted in the fifth giant planet’s ejection from the solar system altogether.

Signs of acid fog found on Mars

2 November 2015 Astronomy Now

While Mars doesn’t have much in the way of Earth-like weather, it does evidently share one kind of weird meteorology: acid fog. Planetary scientist Shoshanna Cole has pieced together a compelling story about how acidic vapours may have eaten at the rocks in Gusev Crater on Mars using a variety of data gathered by instruments on the 2003 Mars Exploration Rover Spirit.

Smoke ring for a halo

2 November 2015 Astronomy Now

Two stars shine through the centre of a ring of cascading dust in this image taken by the NASA/ESA Hubble Space Telescope. The star system is named DI Chamaeleontis, or DI Cha, in the far southern constellation of the Chameleon. While only two stars are apparent, it is actually a quadruple system containing two sets of binary stars.