# Tag Info

## Hot answers tagged mars

12

Our own magnetic field is generated by convection currents in Earth's liquid outer core. A useful summary from Physics.org: Differences in temperature, pressure and composition within the outer core cause convection currents in the molten metal as cool, dense matter sinks whilst warm, less dense matter rises. This flow of liquid iron generates ...

9

Many models shown in books or television show a very populated asteroid belt but in fact the belt is mostly empty. To answer your question, the inclination of the asteroids vary a lot going from 0° to 40° although most off them are in between 0° and 30°; See The orbital element distributions of real and modelled asteroids. So yes it would be 3 dimensional. ...

9

The effect is called apparent retrograde motion. What happens is that Mars has a 'direction opposite to that of other bodies within its system as observed from a particular vantage point' when this loop occurs. That's a bunch of words that don't mean a lot to me. A picture is worth a thousand clearer words: (Imagine this turned sideways and you get the ...

8

Self-sufficiency is an incredibly broad term. We could argue that yes, there is water on the Moon, and that yes, there are viable ways to produce required electricity in self-sustainable ways, but the real question is, are there areas on the Moon that would be viable for both at the same time. You see, the most likely place where surface or near subsurface ...

8

The loss of the Martian atmosphere can be mostly attributed to its mass. The reason why Earth still has an atmosphere made of lighter elements is because with larger mass comes larger escape velocity, which is the speed at which an atom's kinetic energy overcomes the gravitational potential energy of its planet. The distribution of speeds of most gasses can ...

7

The research in other answers helped me come across the actual International Astronomical Union (IAU) standard: The north pole is that pole of rotation that lies on the north side of the invariable plane of the solar system. The north of the invariable plane is the side that Earth's North pole points to. In fact, one of our other users has observed: ...

7

The impact of Phobos, even in one piece (less likely), would be different from Chicxulub. Phobos is probably a little larger than the Chicxulub impactor, but much slower, and comes in almost perfectly tangential. The impact energy would be less than a 10th of the Chicxulub impact, and the energy would be distributed over a large region around the Martian ...

7

We can look up for water in the atmosphere of the planet, not at the planet itself. We can do that when a planet passes in front of a star. That tehnique is called transmission spectroscopy.

6

This is a very interesting question. Of course, as you noted, you have simplified things quite a bit; there are other factors besides temperature that affect habitability. Regarding Venus, you probably know that Venus is extremely hot at its surface not just because it is closer to the Sun, but because it has a thick CO2 atmosphere and is warmed by the ...

6

The most likely candidate would be the Tardigrade. These little guys handle vacuum and radiation just fine. So long as water is provided, according to tests done in LEO the Tardigrade would survive on Mars. Even if they do dehydrate, they spring back to life once water is provided again.

6

On 16 June 2014 at 11:45pm, it was up not far from 220az 30alt. It was actually 232az, 27alt, almost level and to the right of Spica. It would have been easily seen without binoculars being -0.2 visual magnitude. You can answer this sort of question yourself by getting a planetarium app like Stellarium, The Sky X, Sky Safari, or one of many others.

5

That's one of the big questions. ESA scientists, at least, think it's worth looking for underground life. See ExoMars mission. More likely than earth worms are microbes, since some microbes on Earth live under similar conditions as presumed for underground Mars.

5

Mars is the only planet providing rocks with a similar chemical composition and age. So the origin of the meteorite is evident. This doesn't mean, that it's absolutely waterproof. There might have existed protoplanets similar to Mars 4 billion years ago, which since then have been swallowed by Jupiter, the Sun, or have been ejected out of the solar system. ...

4

Additionally, Mars has a much more substantial atmosphere composed of ~95% CO2 (which is one of the major points Zubrin makes), whereas the atmosphere of the moon pales in comparison. Why is this important? Combined with the supply of Hydrogen which would be brought along, you could combine the CO2 with H2 to produce methane (CH4) which can be used as rocket ...

4

Some of the water evaporated, some of it frooze and another good part went into the surface and is now subterranean. For more info read Mars' Vanished Water & Atmosphere --Where Did It Go? and MAVEN’s Quest – Where Did Mars Water Go?. There's much still to learn and experiments in the future will help us to better understand the evolution of mars ...

4

The Tidal acceleration between 2 bodies is calculated with this formula: $$a_T = \frac{2GM_MR_1}{Dm^3}$$ Where $M_M$ is Mar's mass, $R_1$ Earth Radius and $D_m$ the distance to the Moon. If you equal this to Moon's Tidal acceleration you will get $D_M$ as distance to Mars to get the same Tidal acceleration having $\frac{M_M}{M_m}=8.73328184501$:  D_M ...

4

None of these things were named after chocolate. Milky Way The name comes from a Greek myth, at the end of which Hera - Zeus' wife - spills her breast milk. In places where the sky has not been affected by light pollution, the Milky Way looks like a milky-white streak. Hence the name. The chocolate of the same name was introduced in 1923. Apparently, it ...

3

Yes, it is. Mars is bright (-0.14 magnitude) and is in the constellation Virgo. It's the brightest star in this region of the sky (SW during the evening) and should appear as a very bright reddish star at a good altitude. If you need a guide, try to find Leo (W). Virgo is at the left of the constellation.

3

North and south are defined according to the planet's rotation about its axis. A "right hand" rule is used: If you make a fist with your right hand, and orient your curled fingers in the direction the planet rotates, your thumb points north. Alternatively: Standing on the equator, facing the direction the planet rotates, North is to your left. Axial Tilt on ...

3

The escape velocity of Mars is about $5.03 \mbox{ km}/\mbox{s}$ , that of Earth about $11.2 \mbox{ km}/\mbox{s}$ , that of Moon about $2.38 \mbox{ km}/\mbox{s}.$ The escape velocity is an important ingredient for the stability of a planetary atmosphere. From this it's not surprising, that the density of the Martian atmosphere is between that of Moon and ...

3

Go with the Option 1 (135mm) as it has bigger light collecting area i.e. diameter of primary mirror. It will enable you to faint objects and it will also help you to see the dim object under greater zoom eyepiece e.g. 4mm or 10mm.. Also dont let you fool yourself with the bigger numbers advertized by telescope vendors like 238X zoom or 300X zoom... First ...

3

Short answer: Sort of Long answer: One week before the encounter, Wikipedia says no. The comet's nucleus will pass by Mars at a distance somewhere of about 139,000 km from the center of Mars - way too far for any predicted collision. The main tail of the comet, too, will most likely miss Mars by about "10 Mars diameters" - roughly 64,000 km. However, small ...

3

I've written an answer or two dealing with this within the last week, and I can't believe I never thought about this. Great question. These spacecraft are in orbit around Mars, constantly in motion, so they can't very well just pack up and move to the other side of Mars to avoid getting hit with the dust. Believe it or not, they can just pack up and ...

3

How would you get a magnetar close to Mars, within the solar system? OK, let's leave that to one side, but the Earth's magnetic field is of order $10^{-4}$ Tesla at strongest. As the dipole field of a magnetar diminishes as $r^{-3}$ and could be as high as $10^{11}$ Teslas at the surface of the magnetar, at a radius of 10 km, then the magnetar woud need to ...

3

Since the rate of lengthening of the day on Mars is three orders of magnitude less than that of the Earth for a first go at calculating how long it will be before the day lengths are equal we can ignore the change in day length on Mars. The difference in day lengths is $\approx 40$ minutes. The Earths day lengthens by $\approx 1.7$ ms/100 years. Therefore ...

3

From the Nature article, the authors propose two alternative explanations: We used photometric measurements to explore two possible scenarios and investigate their nature. For particles reflecting solar radiation, clouds of CO2-ice or H2O-ice particles with an effective radius of 0.1 micrometres are favoured over dust. Alternatively, the plume ...

2

It's exceedingly unlikely, that human-like species ever existed on Mars, from all we know thus far. It's very likely, that matter has been exchanged between Earth and Mars by asteroids, especially from Mars to Earth, and especially in the early solar system. It's very likely, that Mars was habitable for microorganisms in its early history, although there ...

2

We could err by being 'chauvinists' as Carl Sagan would have said, because we are reasoning taking in account the biology and chemistry of life of 1 planet only: a sample of 1... Before 1995, we thought that alien solar systems would be similar to ours, with small rocky planets closer to the star and giant planets further out. Almost nobody thought about ...

2

The circumstellar habitalbe zone can be defined as the distance range around a star, where the mean temperature of a rotating planet would be between 0 and 100 centigrades, if radiation (heat) received from the star and thermal radiation emitted by the planet form an equilibrium. But that's only a rule of thumb. It has been redefined, and is still disputed. ...

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