The planetary trio has become a quartet this morning, as Venus, Mars and Jupiter were joined by the waning crescent moon. Although it was a little painful to get up at 5:30 a.m., I didn't regret having done so, and was rewarded by this beautiful view above Santiago de Chile.
This is 'Halloween Asteroid' 2015 TB145, as it was approaching Earth, imaged with the Arecibo telescope radar. As it turned out, the space rock measures around 600 meters and rotates once every five hours around its axis. It is thus larger than initially thought.
A 'halloween asteroid' is approaching. First off, regardless what you might hear on 'the internet', there is no danger of a collision with 2015 TB145. The 400-something-meter space rock will pass Earth on October 31, 17:12 UT, at a safe distance of 494,000 kilometers, which is 1,3 times the distance to the moon. Close enough however to be seen with small backyard telescopes - if you know where to look.
Chile is rapidly evolving to become the world's center of observational astronomy. With some of the best international observatories already taking advantage of its exceptional clear (and dark) skies, and with future giant telescopes to be operational within the next decade, the South American country will muster 70% of the world's ground based observational infrastructure in the 2020s.
Alpha Centauri is the nearest star to the unaided eye, and the third brightest of the sky. A small telescope reveals it to be a beautiful double system: two stars similar to our Sun revolve each other in the span of a human lifetime. Because of their relative proximity, angular separation and position angle of the two components change notably in the matter of years, making this system particularly interesting to observe. This year, in November, the angular separation reaches a minimum of only four arcseconds.
On May 23, amateur astronomers across central Europe are in for a treat: Two asteroidal occultations within one hour, without having to change your seat. This is a pretty rare occurrence, as such events are only visible in a rather narrow paths on the ground.
With just 27,5 hours after new moon, Earth's only natural satellite was just visible tonight shortly after sunset. While some folks in Europe managed to see and photograph it only 24 hours after new moon, I had to wait a little longer in southern Chile. It was barely visible in my 10x50 binoculars as it set behind some hills that obscure my western horizon.
Since April 8, Nova Sgr 2015 No.2 is brightening - once again. It might therefore be a similar type of nova as DQ Herculis, a "slow" nova that appeared in the constellation of Hercules in 1934. If this is the case, Nova Sgr 2015 No. 2 may be visible for amateur astronomers for months to come.
The Nova Sagitarii 2015 (No. 2) is still bright, in fact, it has brightened again over the last nights. It is easily visible as a fairly bright 4.5mag star near "lid" of the "teapot" (the asterism that is much more easy to identify than Sagittarius itself). You can find it even without binoculars under bright skies.
Almost exactly one year after the great April 15, 2014 lunar eclipse, the Moon entered Earth's shadow again last night, for what was to be one of the shortest total lunar eclipses possible. Unfortunately, from Chile the event was only partially visible, so unlike 2014 I did not see any red 'bloodmoon', but only a slightly obscured one setting at dawn.
Today I am very happy to announce that an article of mine has been selected as cover story in Sky&Telescope magazine: Surveying Skyglow - or Why are Amateurs needed to help measure the ongoing Spreading of Light Pollution. The full article has been published in the May 2015 issue, which is available digitally here.
European skywatchers have a speacial treat ahead: On Thursday, March 12, 2015, around 01:08 UTC, main-belt asteroid (216) Kleopatra will occult a 8.1mag star in the constellation Crater. The event will be visible in parts of Britain, Benelux, Eastern France, Germany, the Alps region, Italy to Greece, although virtually all European amateur astronomers are urged to make observations.
Ever seen a bolide or a fireball - a really big, bright shooting star? If so, you'll probably never forget it. You might have even tweeted, blogged or facebooked about it. Now, you can also report it via an easy to use report form to the International Meteor Organization (IMO) and make a contribution to science.
Starry skies are a vanishing treasure because light pollution is washing away our view of the cosmos. It not only threatens astronomy, it disrupts wildlife, and affects human health. The yellow glows over cities and towns — seen so clearly from space — are testament to the billions spent in wasted energy from lighting up the sky.