Last Year we had an Interstellar visitor; ‘Oumuamua. Now it seems like it may be alien-tech from another Intelligent civilization. Let’s find out.
Artist’s concept of interstellar asteroid 1I/2017 U1 (‘Oumuamua) as it passed through the solar system after its discovery in October 2017. The aspect ratio of up to 10:1 is unlike that of any object seen in our own solar system.
Artist’s concept of interstellar asteroid 1I/2017 U1 (‘Oumuamua) as it passed through the solar system after its discovery in October 2017. The aspect ratio of up to 10:1 is unlike that of any object seen in our own solar system.
credit- NASA

On October 19th, 2017 observer Robert Weryk at Pan-STARRS telescope, Hawaii during Spaceguard survey found an interstellar object. At first, he thought it was probably a typical asteroid, drifting along in the sun’s orbit. But when he went through the data from the telescope, it became obvious it was something else.

Animation of Oumuamua passing through the Solar System
Animation of ‘Oumuamua passing through the Solar System; Source: NASA

On further observation of objects movement, astronauts found that the object is not from the Solar system. It was our first interstellar visitor.

On October 26th discovery of this visitor was announced and it was called A/2017. Later University of Hawaii team named it ‘Oumuamua’ meaning “a messenger from afar arriving first”.

When it was spotted it was already heading away from the Sun. It was about 33,000,000 km from Earth as was traveling at approx of 45-49km/s relative to the Sun.

Gemini South Telescope Color Composite image of 'Oumuamua. Source: Gemini Observatory
Gemini South Telescope Color Composite image of ‘Oumuamua. Source: Gemini Observatory

Immediately after it’s discovery various telescopes like Very Large Telescope, the Gemini South telescope in Chile, Keck II telescope in Hawaii including space-based telescopes Hubble and Spitzer focused their lenses on ‘Oumuamua.

What they found were astonishing, it appeared to come from the direction of Vega in the constellation of Lyra. Its orbital eccentricity was 1.20 approx. (Eccentricity greater than 1 means object has enough speed to escape Sun’s pull).

It came from above the ecliptic plane of the Solar system. Due to the gravitational pull of the Sun, it reached the speed of around 88km/s and passed South of the ecliptic on 6 September making a sharp turn upward at its closest approach to the Sun on 9 September.

The hyperbolic trajectory of  'Oumuamua
The hyperbolic trajectory of  ‘Oumuamua; Source: Wikimedia

It came 17% closer than Mercury’s closest approach to the Sun. On October 14th it crossed the orbit of Earth at a distance of 24,180,000 km. We didn’t even know that it crossed near us until 5 days have been passed.

Motion of 'Oumuamua on its axes
Scientists conclude that interstellar object ‘Oumuamua must be very elongated because of its dramatic variations in brightness as it tumbled through space. They also conclude that vents on the surface must have emitted jets of gases, giving the object a slight boost in speed, which researchers detected by measuring the position of the object as it passed by in 2017.
Credits: NASA/JPL-Caltech

But it is not it’s amazing speed only which amazed the astronomers but it’s weird shape and size. Its color is reddish similar to objects from the Oort cloud. It is thought to be rocky and strong enough to handle its motion. It is about 800 meters long and highly elongated in the ratio of 10:1. This makes it pretty weird. Asteroids in our solar system also have elongated shape but max ratio observed was 3:1.
Its motion is also not regular, brightness from it varies by the factor of ten as its axis spin every 7.3 hours.

What do we know about it?

1. It is interstellar- It is not originated from the Solar system because nothing in the Solar system can speed it that much and on passing the Earth it’s speed was very fast indicating it was uninfluenced by any other planets.
2. It follows hyperbolic trajectory- Due to its high speed it is not captured by the gravity of Sun, so it is not coming back.
3. It must be elongated- Due to its large distance and fast speed we don’t have its clear picture. But its 10-factor periodic variation in brightness suggest that it is highly elongated.
4. It tumbles- Unusuality in the brightness pattern of this visitor suggest that it is not only rotated about just one axis but also has a second axis with a different period.

What we don’t know?

1. What does it look like? – It came so fast and is very far now thus we didn’t have a chance to have a glimpse of it. When it was observed it was only a single point of light. Thus we don’t know it’s surface features and appearance.
2. What it is made of? – If it was a comet from our Solar system, it would have kicked off lots of dust and gas as it approached the Sun. But it didn’t do any such things. So we don’t know yet what it is made of.
3. Where did it come from?- Scientists had traced its path which seems to originate from Vega star in the constellation of Lyra. But accounting Vega’s proper motion, it would take 600,000 years to reach the Solar System from Vega. But Vega was not in the same part of the sky at that time. So its origin still remains a mystery.
4. What is it doing now? – After January 2018, it is no longer visible to telescopes. So we don’t know what is it doing.

Is it an Asteroid or a Comet?

A Comet showing its Gas and Dust tails as it approaches Sun
A Comet showing its Gas and Dust tails as it approaches Sun, Source: Wikimedia

 Let’s first understand what is a comet?
Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet’s orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles.

Asteroid, IMG source: NASA

And Asteroids, sometimes called minor planets, are rocky remnants left over from the early formation of our solar system about 4.6 billion years ago. Most asteroids are irregularly shaped, though a few are nearly spherical, and they are often pitted or cratered. As they revolve around the sun in elliptical orbits, the asteroids also rotate, sometimes quite erratically, tumbling as they go.

As ‘Oumuamua passed within 0.25 AU of the Sun, it should have developed a coma and a tail as ice and dust vaporized from the surface but no such Coma or tail was observed by the international astronomical community. This makes it a pretty decent contender of being an asteroid.

But further observations from Hubble and other Ground-based telescopes led to a new discovery that ‘Oumuamua was being slightly pushed away from the Sun. Possible reasons were that it could be highly magnetized and thus interacting with solar winds or its center of gravity may be displaced.

The more careful observation showed that there must have been a significant release of gas by sublimation was the main feasible mechanism making it a comet.

Maybe it doesn’t belong to any category as it is first interstellar object with such distinct properties. We can put it in the class of Small body.

Is ‘Oumuamua an Alien Tech?

Is ‘Oumuamua alien tech?

SETI (Search for Extra-Terrestrial Intelligence) and Allen Telescope array examined ‘Oumuamua for radio emissions but they found nothing immediately cutting out the possibility of it being an Interstellar Spaceship.

At least it would visit Earth to say Hello! OR invade Earth.

Solar Sail; Source: NASA

But there have been few theories suggesting that it can be a Solar sail from distant Civilization. There has been a recent study conducted by Shmuel Bialy and Prof. Abraham Loeb indicating the same.

We discuss the possible origins of such an object including the possibility that it might be a LightSail of artificial origin. Our general results apply to any light probes designed for interstellar travel.

An Article in Newshub state that it could an interstellar alien yacht.

“The assumption that ‘Oumuamua followed a random orbit requires the production of 10^15 such objects per star in our galaxy. This abundance is up to a hundred million times more than expected from the solar system, based on a calculation that we did back in 2009 – a surprisingly high overabundance, unless ‘Oumuamua is a targeted probe on a reconnaissance mission and not a member of a random population of objects.”‘Oumuamua was only barely spotted, and Prof Loeb suggests there could be many, many more probes just like it buzzing by, without us noticing.

But as Carl Sagan said

“Extraordinary claims require Extraordinary Evidence”.

What do you think about these claims? Write in the comments.


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