Artist illustration of ‘Oumuamua, the first interstellar object ever spotted in our solar system. (M. Kornmesser/ESO)
There is so much that we don’t know about how the universe works.
Sometimes examples come along that remind us how much. Such As ‘Oumuamua.
Given the Hawaiian name for the ‘pathfinder’ or ‘scout’, it was first discovered in September.
The PanSTARRS1 telescope, a new point of light crossing the sky. It was coming from a strange direction. It was moving unusually fast.
That was traced to an interstellar origin outside our own solar system.
At first, it was the nickname of Comet C/2017 U1. But it turned out not to be a comet. So was the name ‘Oumuamua.
Now astronomers have figured out something about the origin, the incredibly long journey, and her make-up.
The latest revelation is that the spinning chaotically out of hand.
And it is destined to do this for at least a billion years.
A PALPABLE HIT
“At some point or another has been in a collision,” Queen’s University astronomer Dr Wes Fraser told the BBC Sky At Night show after his research was published in Nature and Astronomy.
In the vastness of the space between the planets — but only the interstellar distances between the stars — the odds for this are incredible. But it may be what propelled our way in the first place.
British researchers have the break-down of the light patterns is reflected by the extraordinarily dull object.
Rather, it is set approximately 200 m long. To eight times longer than it is wide, it is approximately the shape of a crumpled cigar.
It was at first thought to run once every seven or eight hours. But the math does not add.
The variations in the dull reddish light is reflected this is far from the object surface can show how it moves. Turns out, it is not moving in a regular pattern.
It is not running quietly along the shaft as most of the known asteroids.
The tumbling is chaotic.
And it probably is to do this for hundreds of millions of years.
“The tumbling is actually caused stress and tensions internal to the object, that slowly but surely, squeezes and pulls on the object, just like the tides on Earth to remove energy from the spin,” Dr Fraser says.
This couple has a new form of the object through the millennia. Eventually, it will soak up all of the energy of the spin, making it glide gently through the room.
But that is still a billion or so years.
This in itself gives ‘Oumuamua is very solid. A chunk of stone or metal. Otherwise it would have fragmented, or soaked spin long before now.
So what is the cause of the spin?
“It is hard to know if it was during the planet’s formation, or after the planet formation process,” he says. “Certainly, more collisions occur while the planets grow than afterwards, so that is a very good bet. But unfortunately, we can not for a high-resolution image of this thing to see what kind of crater is that can be attributed to the collision that caused it to start tumbling.”
The interstellar wind. Heat radiation. Close encounters with planets. All could have contributed to her wild running, in the neighborhood of the eternal dance.
WHAT IS ‘OUMUAMUA
It has led to something of a revolution in astronomy.
It is the first known object in our solar system from deep space.
But the truth is that there are more than likely thousands of such interstellar asteroids captured by the gravity of the Sun. It’s just that we didn’t see coming.
It is estimated that at least one change each year.
Possible, they offer a unique example of the functioning of stars and planets formation in our galaxy.
But Astronomers are still uncertain what ‘Oumuamua actually is.
It looks like a rocky asteroid. It is definitely not flare up like a comet as it passed very close to the Sun (37 million kilometres) from last year.
But it also seems to be thickly coated by organic carbon compounds — probably generated by long-term exposure to harsh interstellar radiation in the space between the stars. This isolating an icy core.
It is also to be seen as potential evidence for the theory of lithopanspermia, the transfer of microbial life between the planets and the stars by comets and asteroids. Such an object crashing into our surface as a meteor can be seeded the building blocks for life on Earth.
We have not yet sampled, such as an interstellar visitor, but still.
So it remains just a tempting idea.
‘Oumuamua itself is not going to hang around long. With the current speed, it will pass Jupiter in May and Saturn in the beginning of next year.
It will not take long until it has our solar system behind.
Meanwhile, astronomers are racing to find the next interstellar visitor. Or the identify of those who are snared by the Sun, by the force of gravity.
This is backtracking orbits. Watching the sky in general, ignored directions. The analysis of the spectroscopy of known objects for variations in oxygen isotope ratios that indicate that they are not made of the same material as the rest of our solar system.
WHY IS ‘OUMUAMA THE WAY IT IS?
The Search for Extra Terrestrial Life (SETI) Matija Cuk do not know. But he does have a favorite idea.
“My own favorite hypothesis is that ‘Oumuamua is a piece of a planet destroyed by water as it was close to the passing of a red dwarf star in a binary system,” he writes.
“The idea is that the planet formed around the red dwarf’ s companion, but the orbit was disrupted and the planet swung along the red dwarf, about to be thrown into the interstellar space.”
“Red dwarf stars can be surprisingly close, some of them are the size of Jupiter, but with a hundred times greater mass. This makes their tides are very strong, and tides can disturb bodies that get too close (such as Jupiter disrupted comet Shoemaker-Levy 9 in 1994).
“If a planet can be fragmented into billions of particles that are then ejected in the interstellar space, such disasters can produce more interstellar objects than the ordinary ejection of comets and asteroids by planets.”
This story was previously published in the news.com.au.