Planets of our Solar System: Mars

Hi,
today I am getting to fourth planet of Solar System since I skipped Earth.
It is Mars, The Red Planet.

Mars is very pretty planet. There are actually nice conditions, really the best for us if we are not counting Earth of course. This makes Mars very kind of nice for research and everything.
We are able to see him in the morning below Venus but it is not really bright. Still if you have good eye you may be able to see the reddish color of its surface, I will get later to it.

Mars orbits 1,52 AU from the Sun. The difference between closest and furthest distance from our star is over 40.000 km compared to Mercury´s 23.000 km and Jupiter´s 76.000 km.

You wont get overheated very much on its surface, there is average temperature about -60°C. Surface color is red, right you guessed it and it because of iron oxide (hematite). It Mars map scale-coloured.pngMapa Marsualso makes sense that people named it Mars, after roman god of war (Greek version is
Ares).

There are two main things about physical geography “up” there. Some time in the past Mars collided with huge rock
which made crater over whole north part. Same on the Moon, lava could easily bubble up through thin crust and smooth everything out (as a proof you can see it on the picture). While on the south there are lot of impact craters.

When you see this map immediately your eye moves to huge red spot on the right, those are mountains, actually volcanoes with tallest mountain in the whole Solar System: Olympus Moons which is 27 km tall with surface area about the size of France. This one and also other volcanoes were made when tectonics of Mars were still active.

Really cool thing is in the middle of map, such a small blue line cutting few kilometers to earth. It is Vales Marineris (picture is from Celestia).
This canyon is crack which was made when the crust was cooling. It is 4000 km long, 200 km wide and 7 km deep.

Water on Mars
You have probably heard of it and I will make sure to make separate post about it.
So yes, NASA found liquid water on Mars. Problem is that it is full of soil so you can call it water, yes but it is more kind of mud which is flowing from season to season with its low freezing temperature. There are also polar ice caps on the poles with little water on them and mostly dry ice (CO2).

Even that Mars has atmosphere, it is extremely week and when it is winter on Mars one third of it is in solid form on surface.
Scientists are sure that there was liquid water before (even oceans) but it evaporated and solar winds blew it away because Mars´s gravity was not strong enough to hold it (Mars has only 0,3G).

Mars has two moons but I will talk about them in different episode since I made this: “Moons of our Solar System” thing.

Dragallur

I also wrote about visiting of Mars

Previous post about Mercury
Previous post about Venus

Celestia: Ultimate space program

Hi,
today I will write about really interesting computer program which is called: Celestia
(maybe this sounds like advertisement, it is not).

Celestia is freeware program, completely. It is simulator of Universe, really good one as everything is made in “real” size.

You will start turned towards Earth but in few moments you will learn how to browse whole Solar system and its moons, comets or asteroids. Celestia gives lot of options like slowing and speeding time. You can see orbits of all this stuff which is lying around. Also you can get really easily out of Solar system but without option: Go to object (Sun), I am pretty sure you will get lost in our Milky Way. You can also see other galaxies but of course you can not visit star by star.

Everything is on you to try it, I found it really fun and still I have not used any “add-on” which can give some bonus stuff to this program.

Dragallur

Debris disk: Ring around star

Hi,
with this post I am answering to one comment posted about three weeks ago on Roche limit.

Could there be rings around sun?

Yes they are called Debris disks. Debris disk is created from nebula which is surrounding young star. This nebula is full of gas and dust. Either all this stuff is pushed away by radiation or planetesimals are created.

Planetesimals are huge rocks, (more than one kilometer across). They do not need Brownian motion anymore to grow because they have enough strong gravity to pull other rocks, and at some point they can be enough large to be planets.

When those planetesimals collide they left dust and rock behind them. This is what isHeic0821f.jpg called debris disk. It is not created by Roche limit as normal planetary ring is and I did not find anything about rings around star that are made by Roche but if I do I will definitely post it here.

This dust in debris disk is usually very small: 1-100 micrometers.
Our sun has this debris disk and you have probably heard about it, it is the Kuiper belt.

There is other example of debris disk and it is around very bright star called Fomalhaut. Ring Around a StarYou can see it on the right top. This star has debris disk which is moved by 1.4 billion miles (roughly 2.24 billion kilometers) to left. It is probably because of huge planet. The dark spot around star (pic. on the left and bot.) is just effect of blocking the light from Fomalhaut so we can see all the debris reflecting photons. This false-color composite image reveals the orbital motion of the planet Fomalhaut b.
Fomalhaut has at least one planet and this one is called Fomalhaut B. On wiki, I am pretty sure there is mistake in one sentence since they are saying that it is star.
You can easily find Fomalhaut on Celestia, I will write about that program probably next time.

Dragallur
PS: I lost.