Astronomers are constantly on the lookout for other worlds that can tell us how the solar system came to be and how special it is. So far, all Earth – like planets have been found in the Milky Way galaxy, but this is the first time an extraterrestrial has been found. In the opinion of the VU astronomer, although the technical possibilities are not enough to find everything about other planets now, we are already in the range of discoveries.

The first planet outside the Milky Way

As the BBC reported, scientists have discovered a planet outside our galaxy for the first time in history. So far, about 5 thousand. Exoplanets – worlds orbiting stars beyond our Sun, but they are all in the Milky Way galaxy.

NASA’s lunar telescope has discovered a Saturn – sized planet in the Vortex (Messiah 51) galaxy. The potential planet is millions of light years away from the Milky Way galaxy.

Scientists call this extracroplanet M51-ULS-1b, and Science Alert writes that its discovery will change the way it searches for planets outside the Solar System – BirdTake, beyond our galaxy.

Finding an exoplanet even in the Milky Way galaxy is quite challenging. In general, the presence of planets orbiting stars in the Milky Way is determined by their influence on the star itself, rather than directly by the exoplanet. The researchers found that the data they collected matched tens of thousands of astronomical units to Saturn-sized exoplanets orbiting distant binary stars.

How do scientists find a new planet?

As VU astronomer Vidas Dobrovolskas told LRT.lt, there are many ways to find planets. The simplest way is to take a picture of a planet near your star. However, the difficulty is that the stars are brighter and the light often obscures the planet, so this can only be done when the star is obscured by something.

“The size of modern telescopes still slightly limits the distance at which planets can be detected using this method. Nearby planets are easy to find. Although direct photography has identified a dozen planets, it represents the smallest proportion of all discoveries.

Another method is called the transit method. In essence, if a planet revolves around its star, its orbit or path passes through it, so that when we look at it from Earth, the planet seems to obscure the star slightly. Most of the planets were discovered by observing the stars and seeing periodic spikes. I do not know the exact number, but almost half of all the planets look like this, “said the astronomer.

The third method, he said, is based on some influence of the planet on the star. As the planets orbit the star, they attract each other – and the planet pulls the star slightly closer to itself. As a result, the speed of the star changes periodically. There are spectroscopic methods that can measure the speed of stars for Earth observation. If we observe the speed of a star changing from time to time, for example, it is a little closer to us, it is farther away, and we can assume that the planet is orbiting even though it is not directly visible.

“As the planet grows, it becomes a star, its magnitude increases with speed, and as it gets closer to the star, it orbits faster, often changing speed,” said V. Dobrovolskas.

The scientist named the fourth method – the more bizarre. For example, if light from distant stars passes close to the planet, its attraction slightly distorts space and the light reflects off like a glass lens.

“This is called the gravitational lens method. Albert Einstein’s theory of relativity predicted that any object of attraction could distort space, in which case the passing rays of light deviate from the straight path. If a solitary orbiting planet fits in with us and a distant background star, the light of that star shines for a short time, minute, or hour.

However, this is a very strange method, so far very few planets have been found in this way. It is complicated that the planet must be in line between us and some distant star, ”the scientist taught at LRT.lt.

Scientists study planets through the light of stars

The planets that scientists have studied are millions, sometimes millions of light years away. How can we study objects that are far away from us that are difficult to understand?

V. According to Dobrovolskas, unlike the planets in the Solar System, it is really difficult to learn more. Therefore, there is only one indirect way left.

“If a planet appears between it and us the moment it flies around its star, a portion of the star’s light passes through the planet’s atmosphere. Depending on the substances it contains, part of the star’s light can be absorbed, i.e., in the spectrum of the star, the color palette begins to lose one or another shade. The so-called spectrum lines appear.

By not observing the planet directly, but by observing how it affects the light of the star, it is possible to determine from what materials the planet is made, whether it contains oxygen, water vapor, or organic matter. So, even if we do not see the planet directly, we can still experience footprints in the light of the stars, “V. Dobrovolskas told LRT.lt.

Research on other planets will help answer one of the greatest questions in human history

According to V. Dobrovolskas, long ago, 30-35 years ago, the only known planets existed in the Solar System. Therefore, scientists have hypothesized that planets orbiting other stars may have similar properties and parameters. However, when the first planets orbiting other stars were discovered, it became clear that the diversity of possible variants was enormous.

Larger planets, such as Jupiter, have been found to orbit their star as Mercury orbits the Sun. V. According to Dobrovolskas, it is important to study how the planets originated in the Solar System and whether our system of planets is unique, perhaps vice versa – as with many other systems, and other planets and their systems. .

“It’s easy for us to understand how unique and special the Solar System is. Of course, the direct link to this problem is the question of whether we are alone in space. But we still do not know whether the right conditions, such as water, the atmosphere, and the right temperature, will be sufficient to sustain life.

So far, the status of existing telescopes is not such that we can tell if there are any signs of life on other planets, such as biological elements. But we are on the verge of discovery as a new James Webb telescope will be launched into space in December this year. Its technical capabilities allow us to more accurately estimate the structure of other planets’ atmospheres. The search for planets close to other stars is inevitable and closely linked to one of the biggest questions in human history – whether we are alone in the universe, or how extensive life is on other planets, ”the VU astronomer shared. Insights.