Tag Archives: Large Synoptic Survey Telescope

What high-speed astronomy can tell us about the galactic zoo

For most of human history, the distant ‘celestial sphere’ was regarded as perfect and unchanging. Stars remained in place, planets moved predictably, and the few rogue comets were viewed as atmospheric phenomena. This began to change with the Danish astronomer Tycho Brahe’s observation of the supernova of 1572 – apparently, a new star – and his studies of the Great Comet of 1577, which he proved was actually a distant object. Nonetheless, the impression of permanence is strong. There are very few astronomical objects that noticeably vary to the naked eye: only the brightest comets, novae and supernovae. For observers in the northern hemisphere, the last naked-eye supernova was in 1604.

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Large Synoptic Survey Telescope will scan the skies for asteroids which threaten Earth

Around 66 million years ago, an asteroid (or a comet) with a diameter of at least 10 kilometers (6 miles) impacted a few miles from the present-day town of Chicxulub in Mexico at around 64,000 kilometers per hour (40,000 mph). The impact triggered a chain of events what it is known today as the Cretaceous-Paleogene (K-Pg) extinction event, also known as the Cretaceous-Tertiary (K-T) extinction, and wiped out three-quarters of the plant and animal species on Earth, including non-avian dinosaurs.

If this Chicxulub impactor happened today, it would wipe out the human civilization. Luckily, events like Chicxulub impact are rare. Asteroids with a 1 km (0.62 mi) diameter strike Earth every 500,000 years on average. But that doesn’t mean we are totally safe. Asteroids with a diameter of at least 140 meters (460 ft) are big enough to cause regional devastation to human settlements unprecedented in human history in the case of a land impact or a major tsunami in the case of an ocean impact.

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