Slashdot Mirror
Europe Goes To Venus; Mars Comes to Us
JamesO writes "The BBC says that the ESA is going to Venus, reusing the Mars Express design.
Also here. Launch seems to be expected in 2005." And knownsense writes "Space.com is reporting that Mars is coming to closer to Earth. It will be closer by around 191 million miles and will end up 85 times brighter about August next year. This apparently is the first time it's been this close since the Neanderthals."
Astronomy is my passion, tech and computers always second. Although planetary exploration is not my forte, I have been paying close attention to all the recent probes/satellites/additions to ISS. Seems to me space agencies are pretty good at getting stuff done even though they're one of the first budgets cut. Cassini will soon arrive at Saturn and I am anxiously awaiting the flood of images from said sattellite.
This is just my guess, but I think that Radiation is a big factor. There was a story posted relatively recently on space.com about how astronauts on the ISS are getting more radiation exposure than they originally thought. And the ISS has earth's magnetic field to shield some of the effects, the trip to mars and back would likely give the astronauts radiation poisoning. Not to mention all the problems with being in microgravity for a year or more.
The article states that next August, when mars gets the closest to it has ever been, it will be 34.6 million miles away from earth. The article later goes on to say that in 1988, Mars went through a similar (though less extreme) event that closed the distance to earth to 36.5 million miles.....Now I know the 2 million miles is still a huge distance when you think about it, but that's barely a 6% difference.
:-)
Agreed. This is mostly a "numerical anomally" rather than something that is visually signficant. Close approaches happen about every 15 years or so, and most of these are probably within a few percent points of this coming distance.
Although, it would be cool to come out side one night and see Mars close enough to find the missing Polar Lander with the naked eye
Mars is often a tough telescope target. Your eye has to be trained to see any significant detail on the disk. Otherwise it will just look like a small orange disk, roughly the size of a penny held at arms length through the scope, with maybe one or two dark but vague splotches and maybe light areas that mark one or both poles or some high clouds. A "slightly dirty pencil eraser edge on" is how I would describe the view.
I was disappointed to see it at the city observatory at the last close approach. My little 60mm scope actually showed more detail (probably because I waited for a better time when it was higher in the sky.)
I would suggest picking a good Saturn night if you ever go to a town observatory. Saturn, the moon, and Jupiter (in this order) make the most impressive viewing targets IMO. Mars will probably disappoint you visually. But it is cool to know you are looking at Mars, dispite the poor view.
However, Saturn varies over time because of the ring tilt from our perspective. If you go during a year with a non-tilt, you won't see much ring detail. Similarly with the moon: it goes through phases (lighting angle), and some phases are not that great in a telescope. Jupiter is probably the only consistent object WRT appearence and appearent size. It won't shrink, darken, or tilt funny on you. Even the Sun's disk changes in activity every 11 years (if you view it through a filter and projection). Although it is true that Jupiter's red spot does fade in and out depending on the type of clouds it is next to, or if it goes behind the planet. But there is more to Big Jup than just the red spot. You can usually see 4 of its moons quite easily (as starlike specs) and at least 2 tannish cloud bands on the planet.
Table-ized A.I.
Is it just me or does that figure seem a little high?
Not really. Astronomical brightness measurements are logarithmic, and they have to be in order for us to notice any difference. A small bright point in the sky that's twice as bright as another one.. the human brain/eyes sees them both the same brightness (for the most part).
To really notice a difference, you need something on the range of 10X (or more) brighter. 85X from its usual appearance isn't THAT different, it'll just make Mars (normally a small red dot) look a bit brighter than Jupiter (a slightly larger red dot). If you've never watched Mars over the seasons, you may not be aware that it does this every coupla years, just not to this extent - the last time it got really bright was in the mid 80's - when Mars was almost as close (to within 2 million miles) as it will be this time around.
It's happened before, it's been measured, and yes, it really DOES get a lot brighter.
Endless arguments over trivial contradictions in books written by ignorant savages to explain thunder in the dark.
- Mars will get 1.20 times closer to the Sun. That makes it 1.20^2 = 1.44 times brighter.
- Mars will get 6.54 times closer to the Earth. That makes it 6.54^2 = 42.77 times brighter.
- Mars is currently a 72% crescent, but will become ~100% full, which means 1/0.72 = 1.39 times brighter.
1.44 * 42.77 * 1.39 = 85 times brighter.You can compare the solar system diagrams:
today
08/27/2003
Most people think "an order of magnitude" is a factor of 10. This is actually wrong, and I think it is the origin of your mistake. An order of magnitude is the old naked eye astronomer estimate of the just reliably distinguishable difference in brightness of two stars. A real astronomical order of magnitude is actually the FIFTH ROOT OF 100, which is a factor of almost exactly 2.5.
If objects differ in brightness by a factor of 2, you can easily tell which is the brightest if you can see them both together.
The factors influencing the brightness of Mars are:
- Its distance from the sun (inverse square law)
- Our distance from Mars (inverse square law)
- The portion of the illuminated surface which we see - the variation is much less than with the moon or Venus because the orbit of Mars is outside our orbit.
I rather think this adds up to a TOTAL POSSIBLE variation in the brightness of Mars of 85:1. It will not be 85 x brighter under optimum conditions, just 85 x brighter than when it is as its dimmest. So don't expect a supernova effect.Panurge has posted for the last time. Thanks for the positive moderations.
Well, that's reasonable to say that the astronomical "order of magnitude" = 2.5.
But the reason most people think "order of magnitude" is x10 is because that's the basic definition of "order of magnitude".
http://whatis.techtarget.com/definition/0,,sid9
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.