Moons of our Solar System: Phobos

today I will write about second moon. This time it is Phobos, the bigger of the two moons of Mars.
His name comes from the son of Ares (Mars) and Aphrodite (Venus). Phobos is really strange, he orbits closer to its planet than any other moon. Every year it is closer by 2 meters so one day, about 50 million years in the future Phobos will either crush onto Mars' Moon Phobos
Mars´s surface or he will be ripped by tidal forces so only ring will be left of him.

Phobos was found in the year of 1877 by Asaph Hall. His surface is one of the darkest of any object in our Solar System (this picture has enhanced colors). There are lot of craters and the biggest has almost the same diameter as whole Phobos. You can see it on the right of the picture and it is called Stickney crater after Asaph´s wife. Temperatures can go from -4°C to -112°C.

Phobos has too low gravity so he could not round himself, that is why he looks as potato. Escape velocity from his surface is 41km/h which means that Usain Bolt would be able to run into space on his own feet. The gravity is 0.000581 of gravity on Earth.

Phobos is small but even than he weights about  10,658,529,896,187,200 kg (or 10.6 quadrillion).

One more strange thing about him is that he is orbiting faster than Mars turns around his axis so he can be seen thrice a day rising from west and setting east.


PS: thanks for those who are reading my blog, I have written 50 posts already!


Planets of our Solar System: Venus

here it comes here it goes, post about planet just little smaller than Earth with atmosphereVenus in approximately true colour, a nearly uniform pale cream, although the image has been processed to bring out details.[1] The planet's disc is about three-quarters illuminated. Almost no variation or detail can be seen in the clouds. so dense that… well it is very very dense.

But first things first: Venus is second planet from Sun. It is sometimes called “The Evil Twin of Earth”. It is rotating around its axis in the opposite direction from other planets which means that Sun rises there on the west and sets on the east. It is rotating extremely slowly so its day is longer than its year (224:243).
Because of this Venus is also most round planet of all planets in solar system, because no strong centrifugal force is expanding planet at the equator.

Venus is third brightest object on the sky after Sun and Moon. She is easy to see right after sunset and before sunrise.

Even that Venus is 110 000 000 km away from the sun she is hotter then Mercury because of its extremely dense atmosphere which is creating tremendous greenhouse effect (and also pressure which is over 60x greater than our). It is possible that in the past there was water on the surface but positive feedback of greenhouse effect did fast process with it. Now over 95% of Venus´s atmosphere is made up by carbon dioxide. Surface temperatures can rise to over 450°C.

Because of so thick atmosphere it was not possible for long time to observe her surface but now thanks to radars we know that there are over 100 000 volcanoes and 167 of them have diameter greater than 100 kilometers. Structures here are named after women or goddesses from different cultures.

Scientists are not really sure why but sometimes there are holes in the atmosphere through which we can see “down”. Every 100 years or so happens the transit of Venus over Sun. It happens in pairs which are 8 years apart and those who missed it as me are very unlucky since next one will be in the year of 2117 (it is so rare because Venus´s orbit is
moved by 3° so it is usually “above” or “below” us.)