Now they've found the GECKO nebula: Image reveals strange dark lizard-shaped cloud lurking in Sagittarius
- Image was taken by ESO's La Silla Observatory in Chile and released today
- It shows the Barnard 86, a small, isolated nebula known as a Bok globule
- U.S. astronomers publish picture of red rose nebula for Valentine's Day
This image shows a mysterious dark cloud in distant space, which scientists from the European Space Organisation have decided looks just like a gecko.
Taken by the Wide Field Imager at ESO’s La Silla Observatory in Chile it shows the bright star cluster NGC 6520 and its neighbour, the dark cloud Barnard 86.
The cosmic pair is set against millions of glowing stars from the brightest part of the Milky Way — a region so dense with stars that barely any dark sky is seen across the picture.
The Gecko nebula: Astronomers at the European Space Organisation released this image of dark could Barnard 86 today. They have decided that it looks like a gecko
This part of the constellation of Sagittarius (The Archer) is one of the richest star fields in the whole sky — the Large Sagittarius Star Cloud.
The huge number of stars that light up this region dramatically emphasise the blackness of dark clouds like Barnard 86, which appears at the centre of this new picture, which was released today.
This object - a small, isolated dark nebula known as a Bok globule - was described as 'a drop of ink on the luminous sky' by its discoverer Edward Emerson Barnard.
WHAT IN SPACE IS A BOK GLOBULE?
Bok globules were first observed in the Forties by astronomer Bart Bok.
They are very cold, dark clouds of gas and dust that often have new stars forming at their centres.
These globules are rich in dust that scatters and absorbs background light, so they are almost opaque to visible light.
In a paper published in 1947, Bok and E.F. Reilly hypothesised that these clouds were 'similar to insect's cocoons' that were undergoing gravitational collapse to form new stars.
More recently near infrared observations confirmed that stars were being born inside them.
They remain a subject of intense research.
An exceptional visual observer and keen astro-photographer, Barnard discovered and photographed numerous comets, dark nebulae, one of Jupiter’s moons, and was the first to use long-exposure photography to explore dark nebulae.
Through a small telescope Barnard 86 looks like a dearth of stars, or a window onto a patch of distant, clearer sky.
However, this object is actually in the foreground of the star field — a cold, dark, dense cloud made up of small dust grains that block starlight and make the region appear opaque.
It is thought to have formed from the remnants of a molecular cloud that collapsed to form the nearby star cluster NGC 6520, seen just to the left of Barnard 86 in this image.
NGC 6520 is an open star cluster that contains many hot stars that glow bright blue-white, a tell-tale sign of their youth.
Open clusters usually contain a few thousand stars that all formed at the same time, giving them all the same age.
Such clusters usually only live comparatively short lives, on the order of several hundred million years, before drifting apart.
Judge for yourself: What a real gecko looks like
The incredible number of stars in this area of the sky muddles observations of this cluster, making it difficult to learn much about it.
NGC 6520’s age is thought to be around 150 million years, and both this star cluster and its dusty neighbour are thought to lie at a distance of around 6000 light-years from our Sun.
The stars that appear to be within Barnard 86 in the image above are in fact in front of it, lying between us and the dark cloud.
Although it is not certain whether this is still happening within Barnard 86, many dark nebulae are known to have new stars forming in their centres — as seen in the famous Horsehead Nebula, the striking object Lupus 3 and to a lesser extent in another of Barnard’s discoveries, the Pipe Nebula.
However, the light from the youngest stars is blocked by the surrounding dusty regions, and they can only