Oort cloud – Astronomy Now

Large, distant comets more common than previously thought

27 July 2017 Astronomy Now

Comets that take more than 200 years to make one revolution around the Sun are notoriously difficult to study, but NASA’s WISE spacecraft, scanning the entire sky at infrared wavelengths, has delivered new insights about these distant wanderers.

Relationship revealed between chemicals found on comets

2 November 2016 Astronomy Now

A new study reveals similarities and relationships between certain types of chemicals found on 30 different comets, which vary widely in their overall composition compared to one another. The research is part of ongoing investigations into these primordial bodies, which contain material largely unchanged from the solar system’s birth some 4.6 billion years ago.

Extreme trans-Neptunian objects lead the way to Planet Nine

13 June 2016 Astronomy Now

In the race towards the discovery of Planet Nine, scientists from around the world strive to calculate its orbit using the tracks left by the small bodies that move well beyond Neptune. Now, astronomers from Spain and Cambridge University have confirmed that the orbits of the six extreme trans-Neptunian objects that served as a reference to announce the existence of Planet Nine are not as stable as originally thought.

A piece of the early solar system returns after billions of years in cold storage

29 April 2016 Astronomy Now

Astronomers have found a unique object that appears to be made of material from the time of Earth’s formation, which has been preserved in the Oort Cloud for billions of years. C/2014 S3 (PANSTARRS) is the first object to be discovered on a long-period cometary orbit that has the characteristics of a pristine inner solar system asteroid.

Chandra sees comets in the “X”-treme

18 April 2016 Astronomy Now

Scientists have determined that comets produce X-ray emission when particles in the solar wind strike the comet’s atmosphere. Recently, astronomers announced the results of a study using data collected with NASA’s Chandra X-ray Observatory of two comets — C/2012 S1 ISON and C/2011 S4 PanSTARRS — when both were relatively close to Earth.

Space-Earth system produces highest-resolution astronomical image

27 January 2016 Astronomy Now

Using an orbiting radio-astronomy satellite combined with 15 ground-based radio telescopes, astronomers have made the most-detailed astronomical image yet, revealing new insights about a gorging black hole in a galaxy 900 million light-years away. The image has the resolving power of a telescope about 62,500 miles wide, or almost eight times the diameter of the Earth.

See Comet Catalina’s close brush with the northern sky’s brightest star

29 December 2015 Ade Ashford

Discovered on 31 October 2013 by the Catalina Sky Survey, C/2013 US10 is an Oort Cloud comet making its first foray into the inner solar system. Currently dashing northward through the constellation Boötes, Comet Catalina passes within ½ degree of Arcturus, the brightest star of the northern sky, on the morning of 1 January 2016.

Sun’s close encounter with Scholz’s Star

18 February 2015 Astronomy Now

Astronomers using large telescopes in South Africa and Chile identify the closest known flyby of a star to our Solar System: a low-mass star system nicknamed “Scholz’s Star” that passed through the Oort Cloud 70,000 years ago.

Trans-Neptunian study suggests Solar System contains more planets

16 January 2015 Astronomy Now

Research conducted in Spain and the UK suggests that at least two unknown planets exist beyond Pluto, whose gravitational influence determines the orbits and strange distribution of objects observed beyond Neptune.