On April 1, it is customary to deceive or make fun of everyone, but I will go against tradition. Even on this day, I cannot afford to deceive the readers. Therefore, I will tell you about the real facts that caused my surprise. Of course, for some, these facts will not become news, but, I hope, at least something can interest everyone. And I also hope that many, like me, and contrary to the precepts of Sherlock Holmes, drag into their brain attic not only the necessary, but also simply interesting. I would be glad if this April Fools' collection forces someone to dig deeper into the sources and double-check my statements.
Temperature in space, in Earth orbit is + 4 ° С
To be precise, not in the Earth's orbit, but at a distance from the Sun equal to the distance from the Earth's orbit. And for a completely black body, i.e. one that completely absorbs the sun's rays without reflecting anything back.
It is believed that the temperature in space tends to absolute zero. First, this is not entirely true, since the entire known Universe is heated up to 3 K, by relic radiation. Second, the temperature rises near the stars. And we live quite close to the Sun. Space suits and spacecraft need strong thermal protection because they enter the shadow of the Earth, and our star can no longer warm them up to the specified + 4 ° С. In the shade, temperatures can drop to -160 ° C, for example at night on the moon. It's cold, but it's still a long way to absolute zero.
Here is, for example, the readings of the onboard thermometer of the TechEdSat satellite, which was rotating in low Earth orbit:
Promotional video:
It was also influenced by the earth's atmosphere, but overall, the graph does not show the terrible conditions that are usually imagined in space.
Lead snow falls in places on Venus
This is probably the most startling fact about space that I have learned not too long ago. Conditions on Venus are so different from anything that we could imagine that Venusians could safely fly to earthly hell to rest in a mild climate and comfortable conditions. Therefore, no matter how fantastic the phrase “leaden snow” may seem, for Venus it is reality.
Thanks to the radar of the American Magellan probe in the early 90s, scientists discovered a kind of coating on the peaks of the Venusian mountains that has a high reflective ability in the radio range. At first, several versions were assumed: the consequence of erosion, the deposition of iron-containing materials, etc. Later, after several experiments on Earth, they came to the conclusion that this is the most natural metallic snow, consisting of bismuth and lead sulfides. In a gaseous state, they are emitted into the planet's atmosphere during volcanic eruptions. Then thermodynamic conditions at an altitude of 2600 m promote the condensation of compounds and precipitation on the hills.
There are 13 planets in the solar system … or more
When Pluto was demoted from the planets, it became a rule of good form to know that there are only eight planets in the solar system. True, at the same time, a new category of celestial bodies was introduced - dwarf planets. These "sub-planets", which have a rounded (or close to it) shape, are not anyone's satellites, but at the same time they cannot clear their own orbit of less massive competitors. Today it is believed that there are five such planets: Ceres, Pluto, Hanumea, Eris and Makemake. The closest to us is Ceres. In a year, we will learn much more about her than we do now, thanks to the Dawn probe. So far we only know that it is covered with ice and water evaporates from two points on the surface at a rate of 6 liters per second. We will also learn about Pluto next year, thanks to the New Horizons station. In general, how 2014 will become the year of comets in cosmonautics,2015 promises to be the year of dwarf planets.
The rest of the dwarf planets are located beyond Pluto, and we will not know any details about them soon. Just the other day, another candidate was found, although he was not officially included in the list of dwarf planets, as was his neighbor Sedna. But it is possible that they will find more, several larger dwarfs, so the number of planets in the solar system will still grow.
The Hubble telescope is not the most powerful
Thanks to the enormous volume of imagery and impressive discoveries made by the Hubble telescope, many have the idea that this telescope has the highest resolution and is able to see details that cannot be seen from Earth. For a while it was: despite the fact that large mirrors can be assembled on Earth on telescopes, the atmosphere introduces a significant distortion in the images. Therefore, even a "modest" by earthly standards mirror with a diameter of 2.4 meters in space, allows you to achieve impressive results.
However, over the years since the launch of Hubble, earth astronomy has not stood still, several technologies have been worked out that allow, if not completely get rid of the distorting effect of air, then significantly reduce its impact. The Very Large Telescope of the European Southern Observatory in Chile can provide the most impressive resolution today. In optical interferometer mode, with four primary and four auxiliary telescopes working together, it is possible to achieve a resolution of about fifty times that of Hubble.
For example, if Hubble gives a resolution on the moon of about 100 meters per pixel (hello to everyone who thinks that this is how you can view Apollo lander), then VLT can distinguish details up to 2 meters. Those. in its resolution, American descent vehicles or our lunar rovers would look like 1-2 pixels (but they will not look because of the extremely high cost of working time).
A pair of Keck telescopes, in interferometer mode, are capable of ten times the Hubble resolution. Even individually, each of Keck's ten-meter telescopes, using adaptive optics technology, is able to outperform Hubble in two times. For example, a photo of Uranus:
However, Hubble does not remain without work, the sky is large, and the scope of the space telescope camera exceeds the ground capabilities. And for clarity, you can see a complex, but informative graph.
Bears in Russia are 19 times more common than asteroids in the Main Asteroid Belt
The American popular science site leads, and Computerra translates curious calculations that show that travel in the asteroid belt is not as dangerous as George Lucas imagined. If all asteroids larger than 1 meter are placed on a plane equal to the area of the Main Asteroid Belt, then it turns out that one stone falls on about 3200 square kilometers. 100 thousand bears in Russia should be distributed one piece for every 170 square kilometers of territory. Of course, both asteroids and bears try to keep closer to themselves and defile pure mathematics with their uneven distribution, but for the sake of a holiday, such trifles can be neglected.