In a global exoplanet observation experiment, NASA’s Kepler K2 mission and Earth-based observatories on six continents hope to survey millions of stars toward the centre of our Milky Way galaxy. Using a technique called gravitational microlensing, scientists will hunt for exoplanets that orbit far from their host star and for free-floating exoplanets that wander between the stars.
Brown dwarfs are objects that are too large to be called planets, yet too small to shine by nuclear fusion. Two German researchers have taken a careful look at the distribution of nearby examples of these “failed stars” and to their surprise discovered a significant asymmetry in their spatial arrangement.
Several recent news stories have reported that a mysterious anomaly in the orbit of NASA’s Cassini spacecraft around Saturn could potentially be explained by the gravitational tug of theorised Planet 9, existing far beyond the orbit of Neptune in our solar system. However, NASA cannot find any unexplained deviations in the spacecraft’s orbit.
Exoplanet KELT-4Ab, about one and a half times the size of Jupiter, orbits the main star of a three-star system every three days. The system’s other two stars orbit each other once every 30 years while simultaneously orbiting the main star — and the planet — once every 4,000 years. The triple star system lies about 685 light-years from Earth.
A near-record 17-billion-solar-mass black hole discovered in a sparse area of the local universe indicates that these monster objects may be more common than once thought. The newly discovered supermassive black hole is in NGC 1600, an elliptical galaxy in the constellation Eridanus some 149 million light-years away.
An international team of scientists has found radioactive iron-60 in sediment and crust samples taken from the Pacific, Atlantic and Indian Oceans. They report that a series of massive supernova explosions occurring between 3.2 and 1.7 million years ago from stars less than 300 light-years away showered the Earth with radioactive debris.
Much of the action on Mars occurred during a period known as the Late Heavy Bombardment about 3.9 billion years ago. Large comets and asteroids raining down on the planet would have produced enough heat to melt subsurface ice, likely enhancing climate conditions enough to make Mars more conducive to life — at least for a time.
New results from NANOGrav — the North American Nanohertz Observatory for Gravitational Waves — establish astrophysically significant limits in the search for low-frequency gravitational waves. This result provides insight into how often galaxies merge and how those merging galaxies evolve over time.
Fast radio bursts (or FRBs) are brief yet powerful spurts of radio energy lasting only a few milliseconds. They were first identified in 2007 and their source has remained a mystery. New research shows that the radio emission believed to be an afterglow from FRB 150418 actually originated from a distant galaxy’s core and was unassociated with the FRB.
Those of us living in cities, towns and villages are subject to varying degrees of light pollution — the inappropriate use of artificial light at night. But we don’t have to lose our stars as there are ways to mitigate the skyglow. Learn what you can do to help during International Dark Sky Week, 4—10 April.
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