SpaceX meets Moon (soon)

private space company SpaceX aka Elon Musk decided to visit make a flyby around Moon in 2018.

Where to start? Well it probably began with two private citizens who were willing to pay many MANY millions of dollars to get a nice trip. Yes, space tourism, exactly.

This trip is planned to be done with Falcon Heavy which is rocket (not build yet) designed by SpaceX and is supposed to have 2/3 of thrust of Saturn V (the rocket that got Apollo to Moon). The crew will stay for about 8 days in Dragov v2 (v standing for version) capsule that is also not tested yet. Both of these things are supposed to be run later this year.

Dragon V2 in hover test [1]

The crew are definitely some rich people but as of now they are staying anonymous. At the end of this year they are supposed to start some training but otherwise the mission will be automated so they wont have to do much stuff.. also that means that they wont do much science either.. only some tests on their bodies but otherwise it really is only “sightseeing” trip.

Why this whole thing though? Well it will add lot of publicity and earn some money and it is place to test Falcon Heavy and D2 capsule[2]. The last time people went to the Moon was in 1972 and this mission is quite similar to Apollo 8 which was also such a flyby.

Otherwise we do not really know much details, SpaceX will have to do a lot to be able to accomplish this goal and right now it is behind schedule.. there were some rocket explosions which slowed the company down. We will see how it looks like in the upcoming months.


[1]When the rocket starts to explode and there are people on board, you need to be able to escape really fast. The capsule was not tested on rocket yet.

[2]Also if part of it is payed by somebody else.. well why refuse?

Picture source: By SpaceX Photos – Dragon 2 hover test, CC0,

Moons of our Solar System: Thebe

continuing in the promised series about moons I will today cover the satellite Thebe, this time I even have some “high resolution” pictures so keep on reading!

There are few huge craters on Thebe. (largest is Zethus with diameter of 40 km)

Thebe is another Jupiter‘s moon. It is quite smaller than Amalthea, with 100 kilometers as mean diameter. It was named for Greek nymph, in both stories I found, she was lover of Zeus (yet again) but in one she was also the daughter of Egyptian king.

It is quite similar to Amalthea, again it is tidally locked, which means that one side always turns toward Jupiter (this is also true for Moon). The surface is probably red what you can not see on black and white pictures of course. We can estimate its mass only based on the similarity with Amalthea, the value you will get is roughly 4*10^17 kilograms.

For the first time its image was taken back in 1979 by Voyager. Later, Stephen  P. Synnott found it on one picture. Four years later the name we use was first used.[1]

The fact that it is blurry wont help you much.

The above picture is the first sign of another moon, but watch out, this one is only shadow.

In background you can see some huge storms on Jupiter.

Another picture of Jupiter but this time Thebe is really visible! (Yeah it is not just filth on you monitor).

Finally, Jupiter has faint rings. These rings have to made up of something. Usually rings are created when some rocks are ripped apart by tidal forces. Also they can be fed over long periods of time be debris that leaves some moons.

Thebe has one very faint ring which is created by the second method. It is three times fainter than the ring of Amalthea which is very faint too. It has diameter of 65k-113k kilometers and it is not so thin (8400 km) as the Saturn’s rings which are even only several meters tall.


References: 1) 2) 3) 4) 5) 6) 7)

PS: the second and third pictures were taken from the same site and official permission should be needed only for commercial purposes, which is not me.

[1]S/1979 J 2 was the original name, though I did not decode it it probably means S=satellte 1979=the year it was found J=Jupiter 2=probably second in row with this designation.

Moons of our Solar System: Himalia

it has been about 4 months since I last posted about moons. The last post was about Amalthea (pretty cool name huh?). I thought that maybe I should resume some of the series so lets see how it will go. (its mostly astronomy blog so no wonder that these things are here.)

If I count right, Himalia has 29 pixels!

Last time I was talking about Jupiter’s moons so I will continue with those. Today the topic is Himalia.

As you could guess, this name is connected to Jupiter (Zeus in Greek mythology). Most of the time all the people (moons) are lovers of Zeus and Himalia is no exception, she was the nymph that brought 3 sons to Zeus, those were Spartaios, Kronios and Kytos.

Though I found that she is good for watching I highly doubt this since the apparent magnitude (how bright it is) is only 14.6 which makes it almost as visible as Charon, the moon of Pluto (15.55).

Himalia is the largest irregular satellite of Jupiter. To be irregular satellite means to be formed somewhere else and be captured later on by the planet. Such moon has highly eccentric orbit which is also inclined and even retrograde. She orbits much further from Jupiter than the other moons I talked about. The distance ranges from 11-13 million kilometers! This is one 15th of the distance of Earth to Sun which is quite a lot for a moon!

Since there are many other objects around Jupiter like Galilean moons that are easier to study (also more interesting) not many missions studied this piece of rock. It was discovered on 3rd December of 1904 by Charles Dillon Perrine. We know some things from spectroscopy, it is similar to C-type asteroid which means that it contains minerals with

Not so good either

water though otherwise such an asteroid is pretty dark. While Himalia is small compared to planets, it has masss of 4.19*10^18 [1]. It’s diameter is not very clear because the closest pictures were taken millions of kilometers away. There are basicly two pictures of this moon, one which you can see above is by Cassini-Huygens and second is by New Horizons (on the right).

It was thought that Himalia has something to do with the disappearance of other even smaller moon Dia when it disappeared in 2000. Dia was luckily found in 2010 so Himalia is innocent.


[1] This does not mean that Himalia is heavy in Solar System, Earth has roughly 6*10^24.

Moons of our Solar System: Amalthea

today I will write about another moon of Jupiter. This is surely not known to larger community because it is much smaller than the Galilean moons. I would like to say that it is beautiful as her name which I really love but the images of its surface are kind of blurry.

Totally beautiful:

Amalthea PIA02532.png

Amalthea was discovered in 1892 by E.E.Barnard (that guy after whom Barnard’s star is named after [1]). What this tells about it? Well it has to be quite big because back then the observations were not so good yet.

It was named after Amalthea, the Greek nymph who nurse Zeus, so once again it has to do with the planet it orbits.


Amalthea if part of one ring of Jupiter, this one is called Gossamer ring. It is orbiting as 3rd satellite from Jupiter as far as we know, at the distance of roughly 181,365.84 kilometers, there is practicly no eccentricity in its movements and it take almost 12 hours to complete one spin. Some of those strange features can be explained by the moon Io.


When I said that it is not small I really meant it: 250 x 146 x 128 kilometers does some stuff. It does not have any geological activity as Io so its surface is heavily covered with craters.

There are some huge ones on its surface which were surely made by violent impact probably changing the orbit of the moon a lot, you can see them on the picture.

Otherwise there is not something too special observed about the surface of the moon, it is cold place but we still have a lot to search there.

The ring in which she orbits is made from her because Jupiter is reaping dust from its surface.

When person would stand on its surface it would see enormous Jupiter over 40° of sky. The gravity there is not so strong compared to our Moon but still great: 58m/s. Jupiter would also be very very bright, 900x brighter than Moon when it is full.


[1] Check out my page about Daedalus mission!



WTF? A conspiracy? 7) Perfect pictures

it has been a long time since I posted about the Moon hoax but today I am returning. So I found that moon hoaxers think that Apollo must be faked because the pictures taken on Moon are strangely good.

Oh wow, that’s right. All of the pictures look like they have been taken by experts who had enough time to put everything right where they wanted. I mean look at it. Buzz saluting during Apollo 11 mission is perfectly placed in the image next to the “waving flag“. And yes there are tens of similar pictures and all of them are so good. OMG!

Fine, it took some time but finally I found the one you can see below.

I mean, ok clearly this picture is not good one, that is obvious since Armstrong steps out of the picture while it is taken.

I am really curious what would hoaxers say to this, it is from Apollo 11 archive

Next one is not good either, the lunar modul is cut on the right.

Fine there is clear mistake on the hoaxer’s side. They assume that they would see a bad picture in magazine? Or in TV? Really that is just so dumb!

Phil Plait on his bad astronomy says that in fox show about moon landing they called some NASA expert on Apollo cameras and they asked him if he knows why those pictures are so good. Well I can imagine that I would not be able to come up with answer right away while someone is recording me for TV show, while trying his best to put me down.

That is all for today.



Moons of our Solar System: Callisto

here it comes, here it goes after a lot of other posts I have decided to write again about moons and this time I continue to really cold piece of giantic rock and 2nd biggest moon of Jupiter and 3rd largest in whole Solar System right after Titan. It is Callisto not The Spear of Vengeance.

Měsíc CallistoCallisto was found with other Galilean moons by Galileo Galilei and independently Marius. Marius gave her this name. Instead of Callisto, Jupiter IV was used. I am really glad that it changed.
Callisto was one of many lovers of Zeus or Jupiter for Roman`s.

As you can see on the picture below, Callisto is really just a little smaller than Mercury.
It is smaller just by few kilometers but it has just a third of Mercury`s weight. As you can see it depends a lot on the stuff from which the object is made.

Callisto orbits at really big distance. 1.88 million kilometers which is almost 1/75 of the distance between Sun and Earth. For moon it is a big number, more than 4 times between Moon and Earth.

It is actually very important that it is so far away because the rest of the Galilean moons are orbiting in resonance which means that they are creating heat in their interior because of friction of the liquids inside.

Callisto can be described as very cold and hard place. There is no volcanism or tectonic activity on its surface to smooth all the features. But there are also no mountains since they are caused by tectonic activity.
Only things you can find there are craters and there is lot of them. Actually the number can not increase a lot because they will almost always overlap so the ones that are old will erode and disappear.

Crater which you can see on the right is called Valhalla crater and this one is the largest. The middle is only 600 kilometers wide but with the rings from the rest of the collision you can say that Valhalla has 1800 kilometers. Another huge guy is Asgard with 1600 km.

The surface is very old and also very cold with temperatures oscillating between -130 and -190 degrees of Celsius.
Most of the surface is covered by water ice.

Under the surface it is assumed that there is thick salty ocean.

Callisto has really thin atmosphere which is made up of carbon dioxide which is the same for Mars. The atmosphere is actually so thin that it has to be powered from dry ice which is evaporating from surface, otherwise it would disappear completely.

There is mission planned to go for Galilean moons in 2020. It is called Europa Jupiter System Mission and it would be founded by NASA and ESA (European Space Agency). More than Callisto, Europa is the moon of interest since there is much higher probability of live because there is this heat from friction.


1st and 3rd picture
2nd picture

WTF? A conspiracy? 6) No blast crater

here it comes, here it goes. Today I will write about another part of conspiracy theory of Moon landing. I know it seems that the list of hoaxes is not ending. And yes it is very long and that is why this hoax is so popular, it seems that there is so many arguments that even if one or two are wrong there is another squad standing behind, it is TRUE. But it will be debunked, I promise!

Today I will talk about the “No blast crater” argument. To this one next picture relates and it is showing lander with circle on the place where should be blast crater.
When all Apollo landings landed it is assumed that they should left a huge blast crater behind since they would fell in great speeds. Also by the way the lander would not survive if it crashed with such a speed to create crater.
Here comes the question: How did NASA managed to not create blast crater?

They DID NOT go so fast when they were landing! As Phil Plait said:

When someone driving a car pulls into a parking spot, do they do it at 100 kilometers per hour?

Not only that they landed in small speeds but also the surface there is right under millimeters of dust hard rock and the gravity of Moon is much smaller (1/6).
The thing is that actually the lander had so big area of its “legs” that there was about 1,5 pound per square inch which is less than when the astronauts were walking on the Moon and that is why they were making footprints.

Some would say that footprints need water to form, but look at flour, it does not need it! It just stays in very steep shapes! This is called angle of repose. Things that have higher friction are able to have higher angle of repose. Also this is changed by gravity.


PS: I am going to make videos on YouTube. Today or in the weekend I will release probably first one so check it out (channel is ScienceAndRationality)!
1st picture:
2nd picture:

Why is the Moon so strange?

here it comes, here it goes. Today I will write about the strange shape of Moon which is actually pretty normal and you probably saw it some day, of course I mean that the strange thing is that it is “turned” by 90° degrees. I saw it yesterday/today during flight from Rio de Janeiro to London. It was very difficult for me to imagine the position of Moon, Earth and Sun to create this. But today I have downloaded Stellarium which seems to be pretty awesome and now it is clear to me so I will try to explain it.

Fine, the problem is the rotational axis of Earth. It is tilted by over 20°. This means that when you are standing on equator you are moving by a huge distance up and down like on rail coaster during day and night (this changes your point of view on the Moon so the lighted part seems to change). When you are far away from equator you are not moving that much. Parallel are not so long, the difference is less and less and when you get on pole it is not moving at ALL! By this move I mean rotating of the part of lighted Moon through its journey since from our point of view Moon seems to be lighted from different sides throughout the day.

Well it was kind of hard for me to find the right words but you can always ask in the comments.

Source of 1st picture:

WTF? A conspiracy? 4) Identical backgrounds

with one day pause I am coming with post about conspiracy theory of Moon landing. Yes again there is another “argument” by those hoaxers which I am going to crush to pieces thanks to awesome Phil Plait and his Bad Astronomy webpage.
This time lets focus on identical backgrounds on two images which were surely taken from very different distances and they must be faked because NASA was too lazy and they used same background twice.

Ok so here are the pictures from Apollo 15. On the first one where you can see more of those mountains there is no moonlanding apparatus and there is this rocky ground. While on the other there is the opposite but on both pictures there are same “backgrounds” used.
Fine here comes the debunktion. On Moon things stuff does not behave as one would execpt. On Earth we can judge distances by things around because we already know their size from experience, like house, shrub or car. But we dont have these things on Moon.
Once I was looking into the heart of Black Canyon in USA. It was one of the best things I have seen in my entire life and the same thing happened, I was not able to judge the distance.. it looked like that the bottom is 200 meters below me, but bottom of Black Canyon can be almost 700 meters (on the picture you can see the tallest cliff in Colorado, it was taken from wikipedia, thanks).

So there are no things by which you could judge the size of stuff which means that you dont really know how far it is + we also judge by the blur of the air. When there is stuff far away it is much less visible but on the Moon there is everything perfectly clear and you dont know if the rock is meter, 2, 200 or 10000 far away. Here is nice video which will blow your mind and show that you simply can not trust your eyes.

This means that the first picture is probably much closer to the mountains but still very very far away since they are on both pictures of identical size.

Check out the debunking of: Flag, Stars. And the prologue.


Moons of our Solar System: Ganymede

Hi,Největší měsíc Sluneční soustavy Ganymede
here it comes here it goes, the post about Ganymede.
Ganymede was in Greece mythology really beautiful guy. Zeus decided that he wants him on the Olymp so he made him waiter. Thats about it, Ganymede is only Jupiter`s moon that is named after male.

With other Galilean moons Ganymede was discovered by Galileo in the year 1610.

Now for some facts, Ganymede is the largest moon of our Solar System. It is so large that if he would orbit Sun instead of Jupiter he would be considered planet. Ganymede has greater volume than Mercury, but is not so heavy (has about half of Mercury`s mass).
Still even with such a low density (1,936g\cm3), he is twice as heavy as Moon.

Ganymede is orbiting Jupiter with really small excentricity even that there are other moons which could be distracting his orbit. Orbit distance is about 1 million kilometers and he is able to go around every seven days. As other moons he is tidaly locked to Jupiter.

When it comes to interior of Ganymede it is very interesting. As you can see on the surface is ice crust (and quartz rock). When you check the first picture you can see that there are mainly two shades, lighter and darker. Lighter seems to be newer and without impact craters. Same as on for example Moon or Mars, some tectonic activity probably smoothed everything out.

Right under ice crust there is REAL liquid water! It was found by Hubble Space Telescope when astronomers found out that aurora of Ganymede should be “changing|waving” by about 6° (caused by Jupiter magnetosphere) while it does only by 2° which is by salty ocean which has huge impact because it is electricly conductive. This ocean`s volume is larger than of Earth`s volume, it is 100 kilometers deep.

Ganymede is the only known moon to have its own magnetosphere. It is created by convection of liquid interior of Ganymede (it was first discovere by the satellite Galileo). Convection is process which for example occurs in ocean when cold water goes up where it heats and then sinks again, then its temperature drops and whole process repeats.

Ganymede was created in the accretion disk of Jupiter when whole Solar System began to form. Because he was formed closer to Jupiter than Callisto, liquid and solid parts more easily separated. It took 10,000 years to form him. Example of accretion disk is on the right.

Ganymede, Europa and Io are in orbital resonance. This means that are in some (1:2:4) ratio of orbits. For one Ganymede`s rotation there are two rotations of Europa and four of Io. I found gif of this on wikipedia and I could watch it whole day (not to scale). This resonance also causes heating of their interior because of friction.

First mission to which saw Ganymede from close look was Pioneer 10 and 11. Then Voyager had much better look and finally Galileo (and then New Horizons). For the year of 2020 is planned another mission which would orbit Jupiter.


plus wikipedia pages like Ganymede, Orbital resonance..