today I am going to write about proposed mission to investigate Europa.
Europa Multiple-Flyby Mission is a plan consisting of orbiter and a lander directed towards Jupiter‘s moon.
The reason why to choose Europa is quite clear. There is probably liquid water under its surface and if one launches such a thing, it might get public’s attention. (Which might be now more important than ever considering how Trump wants to cut down NASA’s budget especially on the most important thing that they do: Earth’s climate monitoring.)
First of all the orbiter, which would be launched in the next decade, would learn as much as it could about the surface of the moon, Jupiter’s magnetosphere (see later), weird water
This is two images of course. The original does not have the Europa in middle but only black spot. You can see the plumes on roughly 7 o’clock.
plumes and so on. There are 9 instruments together planned.
Instruments on those orbiters are able to collect data faster than we can receive it. This is because there are more mission that need attention of our receivers. Those are not some small receivers but specialized ones and all missions have some time to send information. For example New Horizons, just from its flyby of Pluto kept sending data for some 6 months.
In case of Jupiter oriented mission this might be a problem because Jupiter has extremely strong magnetosphere which will probably damage the instruments in matter of few weeks. This way it is best to get close to Europa and then get away as soon as possible and send the data later. This can not be done for the lander so it really lasts in matter of days. (Yes, it is still a problem even if you cover your equipment under 150 kilograms of titanium as is planned!)
The lander is thing planned even further into future, around 20 years or so. Much can change and we will see what the priorities are at that point.
People will probably get quite excited by mission promising founding signs of extraterrestrial life.
as the title suggests I will be talking about the mission Voyager 1 and 2. I never mentioned them in separate post until today. It is also connected with my presentation I had on the contest.
What are those missions anyway?
Those are two space missions that had quests to check out furthest planets of our Solar System. Because of rare occasion, Voyager 2 was able to check out 4 planets (+ Earth).
Right now both Voyager 1 and 2 are still capable of transmitting signal because their battery working on radioactive materials is still ok, it is not much though, not pictures or something like that.
Both were launched in the year of 1977 and are about 19 billion kilometers away from they Earth.
The thing is that both missions are very cool and they collected lot of data but they also have this “Voyager golden record”. It is record of “The sounds of Earth” which are voices from various languages and also the plate contains some information on how to play it and where in Universe it was launched from.
I know that this was not the main reason for the mission to be launched but at the same time it was not really well made up.
Above you can see the information on how to play the record. How could anyone in the hell know what is this supposed to do? I mean, how can we know that aliens have similar technology like us and that five pictograms can explain how to use it!
There are also images on this thing! There is image of woman in supermarket, photo of Jupites and so on (you can check it out here).
The left circle explains in binary how fast it should be playing. Than the wave is typical frequency of the sound that should come out and under it is something called “scan triggering” (wut?). The boxes under it represent how the image is made and the circle is the first picture that should appear. The lines represent the position of Sun compared to 14 brightest pulsars out there and the two circles represent two hydrogen atoms.
Though this whole thing seems a bit dumb to me, I at least like that they included piece of uranium so that “alien” can know how long it is flying (via radioactive decay).
this is very abstract title I guess but it summarizes why I did not post last Saturday when I planned, yes I am sorry. Anyway I was on this contest called Green trail, golden leaf which is contest of mostly biology though there is also astronomy, meteorology (not this year) and geology. I was not contestant for the first time, but organizator and I helped with astronomy site.
There are two categories which are basicly for older (10-15) and younger (0-10) kids (numbers are rough). The contest happens in groups of 6 people. They are then walking the trail three at a time, getting points on various sites on various topics and finally their points add up.
In Friday I had actually presentation first. I was pretty happy how I did it except that it was a little bit too long. The problem was that even that the presentation was for roughly 50-60 minutes the kids were discussing and asking questions a lot (which made me happy of course) but finally the presentation was roughly 100 minutes.
I was talking about the view on Earth, geocentrism, heliocentrism, no centrism at all and why the Universe is so big and why people usually think it is not. I followed up with aliens and Fermi paradox, of course wow signal and KIC xx… were also mentioned. In the end I mentioned SpaceX, terraformation of Mars, New Horizons and Voyager.
As I said the presentation was going pretty good as well as the contest itself. For younger kids we had questions like:
- Name 3 astronauts
- What is astronomical unit and what is light year
- Name 3 missions (Apollo and other count as 1)
- Name 4 constellations that are visible in Czech Republic
- Highest mountain in Solar System and where it is
- Where do comets come from?
- Difference between meteorite, meteor, meteoroid and asteroid.
- … (and other)
For older it was bit more difficult:
- What is afelium and perihelium
- Name all Galilean moons and give a small info for one of them
- What is HR diagram
- (Lot of pictures about life time of star)
- Draw the orbit of typicall comet and draw both tails and name one place where they come from.
- … (and other)
From 12 sites astronomy was the 2nd toughest 😀
Lets see how would you do, I will return to it some other post.
Today I will write about transit photometry.
This is method of finding exoplanets (means those which are not in our Solar System).
Of course we can not see any of those planets because they are too small. But what we can see or better what can Kepler Space Telescope see is effect of such a exoplanet when it transits around its star. To see this clearly, watch this video.
To describe it with words, when planet transits (orbits) star and Kepler is watching it he will see the little difference in its brightness, some of the light will be blocked by some planet. When this happens periodically we know that there is some planet.
Of course this has some limitations, we can only see objects that are orbiting close to its star because no telescope or satellite has service life of 30 years which would be needed
for Saturn if some extraterrestrial life would watch Sun. Those 30 years are counting with Saturn transiting Sun at the time of telescope´s start.
So this is transit photometry which can be used only for enough large planets that are not really far away from their stars. Usually scientist are mostly trying to find planets in “life zones”. Those zones are in some fixed distance depending on the type of star and it means that we think there could be live. There is lot of candidates for habitable planets and probably best of them is Kepler 452b which is orbiting G type star (same as Sun).
Because legendary Kepler is getting old and he is able to watch only fixed part of sky there is TESS (Transiting Exoplanet Survey Satellite) which will be able to watch 90%.
In the year of 2024 there will also come PLATO (Planetary Transits and Oscillations of stars). This mission is planned for six years but still it will no be able to find planets with the size of Mars or Mercury.
Last one is NGTS (Next Generation Transit Survey) which is trying to find planets smaller than Neptune around stars with apparent magnitude lower than 13 (7 is not visible to average human eye).
Also astronomers can find out how big is exoplanet by its gravitational effect on star and from this we can even count what is its density.