Before the waxing crescent Moon of the next lunation gets too bright, Northern Hemisphere observers get the chance to track a relatively bright and recently discovered Amor-type asteroid that passes just 0.02037 astronomical units (1.893 million miles, or 7.93 lunar distances) from Earth at 15:43 UT (4:43pm BST) on Monday 29 May 2017.
Believed to be between 350 metres and 780 metres in diameter and orbiting the Sun every 4.21 years, near-Earth asteroid 2017 CS was discovered by Pan-STARRS 1 on 2 February 2017. Photometric results indicate a rotation period of about 40⅓ hours with a lightcurve amplitude of 0.18.Given its size and proximity, 2017 CS could attain magnitude +13.5 at closest approach if the predictions tabulated at the bottom of this page hold true. This means that the asteroid is a viable target for 6-inch (15-cm) and larger telescopes as it moves against the background stars at a rate equivalent to the apparent width of the full Moon every hour.Astronomical twilight now lasts all night for observers in the British Isles, except for those in the southernmost counties of England, so the darkest skies are found between midnight and 2am BST. The light of the waxing cresent Moon will also start to interfere from 31 May.
For observers in Western Europe, the following four detailed finder charts for successive nights around the time of closest approach should help you track down this fascinating small world.
Chart 1: 29 May — covering 11pm BST on 28 May to 3am BST on 29 May
Chart 2: 30 May — covering 11pm BST on 29 May to 3am BST on 30 May
Chart 3: 31 May — covering 11pm BST on 30 May to 3am BST on 31 May
Chart 4: 1 June — covering 11pm BST on 31 May to 3am BST on 1 June
Astronomers at Goldstone (and possibly Arecibo) plan to make radar observations of 2017 CS in late May that could yield a surface resolution of 3¾ metres if the signal-to-noise ratios are strong enough.
If you miss 2017 CS this time around, its next close encounter with Earth occurs on 17 May 2038 when the asteroid passes 0.0249 astronomical units, or 2.3 million miles (9.7 lunar distances) from our planet.
The Minor Planet Center classifies 2017 CS as a “Potentially Hazardous Asteroid.”
This NASA/ESA Hubble Space Telescope image shows the galaxy Messier 94, which lies in the small northern constellation of Canes Venatici (the Hunting Dogs), about 16 million light-years away. Within the bright ring or starburst ring around Messier 94, new stars are forming at a high rate and many young, bright stars are present within it.
Discovered by the Catalina Sky Survey on 6 October 2013 a week before its last close flyby of Earth, 30-metre-wide asteroid 2013 TX68 was initially thought to pass by Earth again on 5 March 2016. Additional observations of the body have now been obtained, refining its orbital path and moving the date of the asteroid’s close brush with our planet to 8 March.
This image, taken with the Wide Field Planetary Camera 2 on board the NASA/ESA Hubble Space Telescope, shows the galaxy NGC 6052, located around 230 million light-years away in the constellation of Hercules. It is a “new” galaxy in the process of forming, the result of a merger between two separate galaxies that were gradually drawn together by gravity.