Space History

The magnificent spiral galaxy NGC 4565 is visible from the edge of the planet Earth. Because of its thin profile, it is often called the Needle Galaxy. The bright galaxy NGC 4565 is a good object for observations in the northern sky. She is in the faint but elegant constellation of Veronica’s Hair.

This image shows the central bulge of the galaxy intersected by bands of light-absorbing dust adorning the thin plane of the galaxy. The distance to NGC 4565 is about 40 million sv. years, and its size reaches 100 thousand sv. years.

NGC 4565 can be easily seen even with a small telescope, and lovers of contemplating the sky consider it a real heavenly treasure that Messier did not notice.

The fact is that the rotation of the Earth around its axis is accompanied by the rotation of the axis itself (as the axis of a slowing spinning top begins to rotate). This effect is called precession. The precession cycle is about 28,000 years and is also known as the Platonic Year.

That is, a fixed point in the starry sky also moves in a circle, but very slowly. A similar fixed point in the sky of the southern hemisphere is not so lucky and there are no bright stars nearby. For primitive navigation, the Southern Cross constellation is usually used.

Whenever you look at the night sky, the North Star will show you the way to the north

However, this was not always the case.

14 thousand years ago, its place was occupied by the star Vega from the constellation Lyra, and it will take it again in 13,727.

Until now, researchers have not found evidence of global tectonic activity on planets outside the Solar System. However, recently a group of researchers found evidence of flows inside the planet LHS 3844b. It is located 45 light-years from Earth.

“It is very difficult to observe signs of tectonic activity, because they are usually hidden under the atmosphere,” explains the scientist. However, recent results have shown that LHS 3844b probably has no atmosphere at all. This rocky world, which is slightly larger than Earth, orbits very closely around its star. Because of this, one side of the planet is in constant daylight, and the other in constant night. Similarly, the same side of the moon always faces the Earth. However, the “dark” half is illuminated by bright volcanic eruptions.
Due to the lack of an atmosphere protecting the planet from intense radiation, its surface reaches 800 °C. The night side freezes. The temperature here may fall below -250 °C.

In early 2016, an “ice guest” from the outer Solar system passed by Earth. It was briefly observed in the sky as comet Catalina, after which it flew past the Sun to leave the Solar System forever. Using infrared instruments, the SOFIA Observatory was able to capture a characteristic spectral feature of carbon atoms inside the dust-rich luminous tail of the comet. Now this “one-time visitor” to the inner Solar system is helping astronomers explain the origin of life on Earth, because its study has shown that comets like Comet Catalina could be an important source of carbon, and then life on planets such as Earth or Mars, in the early years of the formation of the Solar System.

Although carbon is the basis of the carbon skeletons of biological molecules of all life forms, however, the early Earth and other terrestrial planets of the Solar System were too hot during the formation period, so elements such as carbon were eventually lost by them into space.

“Carbon is the key to understanding the origin of life, we are not sure that the Earth itself could capture the necessary amount of carbon during formation, so carbon—rich comets could be an important source of this element required for the formation of life” – the main author of the study, Charles Woodward.

According to one theory, the nuclei of galaxies are primary black holes, around which galaxies formed from the matter formed during the Big Bang. Just as planetary systems formed from a gas-dust disk around a star.

Let me remind you. A primary black hole is a hypothetical type of black hole that was formed not due to the gravitational collapse of a large star, but in superdense matter at the time of the initial expansion of the Universe.

In 2018, astronomers discovered an unusual galaxy NGC 1052-DF2 in the vicinity of the Milky Way. With similar sizes to our galaxy, it contains 200 times fewer stars. At the same time, there is practically no dark matter in it. Its presence can be determined by the gravitational effect on visible matter.

It is believed that dark matter is a key component necessary for the formation of galaxies. Without it, the primary gas would not have sufficient gravitational attraction to begin to contract and form the first “star islands”. A year later, astronomers discovered another “empty” galaxy NGC 1052-DF4, containing almost no dark matter.

In an attempt to explain the existence of galaxies without dark matter, scientists have conducted a number of studies and concluded that in the event of a galactic collision, it can “fly out” beyond its galaxy and continue moving through space.

The probability of such a scenario confirms that NGC 1052-DF2 and NGC 1052-DF4 are moving away from each other and there are several other dwarf galaxies next to them that can be lined up in a single line. This suggests that they may have the same origin.

Some time after Pluto was “demoted” from planets to dwarf planets, the International Astronomical Union decided to sweeten this bitter pill for the poor man and introduced a new category of trans-Neptunian objects named after him.

Plutoids now included all dwarf planets orbiting the Sun in an orbit with a radius greater than the radius of the orbit of Neptune, which are in hydrostatic equilibrium and have not cleared the space around their orbit. At first, the honor of becoming plutoids was awarded to as many as two celestial bodies — Pluto itself and Eris. A little later, Makemake and Haumea joined them. Quavar, Sedna, and some other objects are candidates for plutoids.

Even with very large telescopes, Pluto is difficult to detect among the surrounding stars. Therefore, to observe this object, you need to choose zones with a minimum level of illumination and very powerful observation tools.