Scientists May Have Discovered the First Planets Outside the Milky Way (washingtonpost.com)

Using data from a NASA X-ray laboratory in space, Xinyu Dai, an astrophysicist and professor at the University of Oklahoma, detected a population of planets beyond the Milky Way galaxy (Warning: source may be paywalled; alternative source). The planets range in size from Earth's moon to the massive Jupiter. From the report: There are few methods to determine the existence of distant planets. They are so far away that no telescope can observe them, Dai told The Washington Post. So Dai and postdoctoral researcher Eduardo Guerras relied on a scientific principle to make the discovery: Albert Einstein's theory of relativity. Einstein's theory suggests light bends when tugged by the force of gravity. In this case, the light is coming from a quasar -- the nucleus of a galaxy with a swirling black hole -- that emits powerful radiation in the distance. Between that quasar and the space-based laboratory is the galaxy of newly discovered planets. The gravitational force of the galaxy bends the light heading toward the Milky Way, illuminating the galaxy in an effect called microlensing. In that way, the galaxy acts as a magnifying glass of sorts, bringing a previously unseen celestial body into X-ray view. In a university news release, Guerras had a less formal way to describe the complicated process: "This is very cool science."

Comments

Like detecting a butterfly across the ocean

[Camembert]

Many of us are so jaded and cynical these days, yet no matter how you look at it, this is indeed very impressive. It is like standing at the coast in France and noticing a butterfly in New York. Very cool.

Re:Like detecting a butterfly across the ocean

[DrTJ]

No, this is far, far, far more impressive than that.

These planets are (according to the article) 3.8 billion lightyears away, i.e. 3.5*10^22 km. At that distance, a planet appears to be *extraordinarily* small.
If we take your France - New York example (Paris-New York = 5681 km), an earth-sized planet (included in the size range mentioned in the article) would - from Paris - have an apparent size of 2*10-15 m.

I.e. the same size as an alpha particle (Helium nucleus).

"This is very cool science" - Indeed!

Re:Like detecting a butterfly across the ocean

[Anonymous Coward]

I recently started to do a "fun" calculation with energy when it comes to those kind of distances.
First I imagine a radio transmitter or a laser with a frequency and an energy output, for example 50kW and 1MHz.
The output power divided by the frequency times planck's constant gives us the number of photons emitted per unit of time.
Divide this value by the area of a spherical surface and set the radius to the distance we are talking about, like 3.8 billion light years in this case.
Now we have the number of photons that hits a surface area every time unit.
So if you place an antenna with a surface area of one square mile over there it will receive one photon from the KOMO radio station every million years or so.

Increasing to signal strength to 1.21 gigawatts won't really do much to make the signal detectable, neither will directing the signal to a few millidegrees.

Re: Until we can actually go there...

[Anonymous Coward]

"Until we can go there" would be the same fallacy as saying electrons are not science until we can see them with our naked eye. Confidence in theories comes in a continuum, not some binary threshold. In this case, there is quite a history of microlensing studies, which did include hypotheses about what would be seen. The results are not as certain as the existence of the electron, but a lot more so than some math thrown together without new evidence.

Re: Until we can actually go there...

[MightyYar]

They have actually tapped into God's wrath, which we model mathematically as "electrons".

Incidentally, you can really piss off God by rubbing a balloon on your head.