The best images yet of a bizarre dog bone-shaped asteroid named Kleopatra have been taken by astronomers, revealing the rock is larger than previously thought.
The mostly-metal asteroid orbits the sun between Mars and Jupiter, and is 168 miles long by 58 miles wide, making it twice the size of Hadrian’s Wall. Previous estimates put it at 134 miles long by 58 miles wide.
The bizarre space rock looks like a giant dog bone and has fascinated stargazers since it was first discovered in 1880 by Austrian astronomer Johann Palisa.
It is made up of two lobes connected by a thick ‘neck’, and the new images, captured by the European Southern Observatory’s Very Large Telescope in Chile, reveal the bizarre asteroid from different angles as it rotates.
They were taken at different times between 2017 and 2019, with an international team led by the SETI Institute in Mountain View, California processing the images.
Kleopatra is 125 million miles from Earth at its closest, meaning that its apparent size in the sky is equivalent to viewing a golf ball about 25 miles away.
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These eleven images are of the asteroid Kleopatra, viewed at different angles as it rotates. The images were taken at different times between 2017 and 2019
This image provides a size comparison of the asteroid Kleopatra with Chile, where the VLT telescope used to capture the images of the asteroid is located
KLEOPATRA: DOG BONE SHAPED SPACE ROCK WITH A PAIR OF MOONS
Kleopatra is a metallic, bone-shaped asteroid with a pair of moons sitting 125 million miles from Earth.
It is located in the asteroid belt between the orbits of Mars and Jupiter.
It was discovered on 10 April 1880, by Austrian astronomer Johann Palisa at the Austrian Naval Pola Observatory, in what is now Pula, Croatia.
It is 168 miles across and 58 miles wide, with recent observations showing it is mostly a pile of rubble.
It was named after Cleopatra, the famous Egyptian queen.
Two small moons were discovered in 2008, and later named Alexhelios and Cleoselene after Cleopatra’s children.
Facts and figures
- Discovery: 10 April 1880
- Dimensions: 168 miles by 58 miles
- Aphelion: 3.4951 AU
- Perihelion: 2.0931 AU
- Abs Magnitude: 7.30
- Moons: Alexhelios and Cleoselene
Lead author Dr Franck Marchis said Kleopatra is truly a unique body in our Solar System, and the new observations offer more detail on its makeup.
‘Science makes a lot of progress thanks to the study of weird outliers. I think Kleopatra is one of those and understanding this complex, multiple asteroid system can help us learn more about our Solar System,’ said Dr Marchis.
In September 2008, Marchis and collaborators announced that the unusual asteroid has two moons, which were later named Alexhelios and Cleoselene, after Cleopatra’s children Alexander Helios and Cleopatra Selene II.
The new VLT observations identify its dimensions and mass more accurately than ever before – also shedding light on how its orbiting moons formed.
Kleopatra is believed to be the remnant of an incredibly violent collision between two asteroids that did not completely shatter and disperse.
The international team created 3D models based on the various snapshots captured by the VLT, finding that one lobe is larger than the other.
A second study also showed Kleopatra’s density is only 3.4 grams per cubic centimetre – rather than an earlier estimation of 4.5 grams.
That density is half that of iron, meaning that the strange asteroid is about a third less massive than previously thought, and the moons are in a different location.
Professor Miroslav Broz, of Charles University in Prague, said finding the position of the moons was wrong had to be resolved, ‘because if the moons’ orbits were wrong, everything was wrong, including the mass of Kleopatra.’
The new data and sophisticated modelling enabled the international team to precisely describe how Kleopatra’s gravity influences the complex movements of AlexHelios and CleoSelene.
The mostly-metal asteroid orbits the sun between Mars and Jupiter, and is 168 miles long by 58 miles wide, making it twice the size of Hadrian’s Wall. Previous estimates put it at 134 miles long by 58 miles wide
The low density suggests Kleopatra has a porous structure and could be little more than a ‘pile of rubble’, adding to evidence it was likely formed when material came back together following a giant impact.
The team also discovered that the asteroid is spinning around at great speeds, such that if it were going any faster it would begin to fall apart, and any tiny impact from another space rock could send pebbles off into space.
Marchis and his team believe that those pebbles could subsequently have formed AlexHelios and CleoSelene, meaning that Kleopatra has truly birthed its own moons.
ESO’s upcoming ELT (Extremely Large Telescope) will be even more ideal for imaging distant asteroids such as Kleopatra.
This image provides a size comparison of the asteroid Kleopatra with northern Italy
This processed image, based on observations taken in July 2017, shows the two moons of the asteroid Kleopatra (the central white object), AlexHelios and CleoSelene, which appear as two small white dots in the top-right and bottom-left corners of the picture
Added Dr Marchis: ‘I can’t wait to point the ELT at Kleopatra, to see if there are more moons and refine their orbits to detect small changes.’
Kleopatra is one of several dozen asteroids whose colouring suggests they contain metal due to its strong reflection of radar signals.
These objects were once heated, melted and differentiated into structures containing a core, mantle and crust, much as the Earth was formed.
Unlike Earth, those asteroids cooled and solidified throughout, and many underwent massive collisions that exposed their metallic cores.
In some cases, those collisions launched fragments that eventually collided with Earth, becoming iron meteorites like the one that created Meteor Crater in Arizona.
The findings appear in two papers in the journal Astronomy & Astrophysics.
THE VERY LARGE TELESCOPE IS A POWERFUL GROUND-BASED INSTRUMENT IN CHILE
The European Southern Observatory (ESO) built the most powerful telescope ever made in the Atacama Desert of northern Chile.
It is called the Very Large Telescope (VLT) and is widely regarded as one of the most advanced optical instruments ever made.
It consists of four telescopes, whose main mirrors measures 27 feet (8.2 metres) in diameter.
There are also four movable six feet (1.8 metre) diameter auxiliary telescopes.
The large telescopes are called Antu, Kueyen, Melipal and Yepun.
The European Southern observatory (ESO) built the most powerful telescope ever made in the Atacama Desert of northern Chile and called it the Very Large Telescope (VLT).
The first of the Unit Telescopes, ‘Antu’, went into routine scientific operations on April 1, 1999.
The telescopes can work together to form a giant ‘interferometer’.
This interferometer allows images to be filtered for any unnecessary obscuring objects and, as a result, astronomers can see details up to 25 times finer than with the individual telescopes.
It has been involved in spotting the first image of an extrasolar planet as well as tracking individual stars moving around the supermassive black hole at the centre of the Milky Way.
It also observed the afterglow of the furthest known Gamma Ray Burst.