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If the Earth were 100 pixels wide

distancetomars.com

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Re: If the Earth were 100 pixels wide

#131

Post by cyanoacry »

shardling wrote: post #32

It bothers me a little that they show the motion against a starfield like that -- the stars are so far away that they won't shift perceptibly even on a journey to mars. I mean, I don't have any better ideas, but given that the whole point is to give an idea of scale I wish they'd come up with something else. :)

I think the best thing to do would be to provide periodic asteroids or rocks that go across the screen every now and then---it's very difficult to get a sense of speed with a repeating star field, not even including the fact that this wouldn't happen in the first place.

Since the starfield was periodic, it looked to me as if it were staying still or moving backwards at times (the wagon-wheel effect[1]) :(

[1] http://en.wikipedia.org/wiki/Wagon-wheel_effect

Re: If the Earth were 100 pixels wide

#132

Post by Steuard »

primitur wrote: post #100
ohazi wrote: post #51

Is anyone else a little bothered by the fact that the reported speed was 1/5 the speed of light, yet the flyby necessarily increased to well over the speed of light in order to actually get you to Mars before you got bored and closed the tab? Traveling at the speed of light would have taken 5-20 minutes. Traveling slower than that would have taken even longer...

I'm more bothered by the authoritative fact that 'the timeline for a manned mission to Mars is the 2030s'. Says who, NASA? They're not the only ones trying to get there.

Essentially all Mars missions under serious consideration rely on special alignments of planetary orbits to minimize the fuel required. That leads to very specific "launch windows" that may only occur every few years. For an Earth-Mars trip, the basic launch window is available roughly every two years, but there are particularly low-energy opportunities every 16 years or so.

My understanding is that the next of those will be the 2018/2020 launch windows, which is almost certainly too soon for a mission to be ready. So the following low-energy opportunities will be somewhere in the mid 2030's. That's not to say that it would be impossible to use a launch window in the mid-2020's despite the higher fuel cost (or even some other orbit entirely that didn't try to minimize fuel at all), but doing so would be substantially more difficult.

Here's a link that is useful primarily because it links to more thorough discussions: http://en.wikipedia.org/wiki/Exploration_of_Mars#Launch_wind...

Re: If the Earth were 100 pixels wide

#134

Post by 3327 »

jerf wrote: post #18
3327 wrote: post #2

if I leave it running will I get to mars? just out of curiosity? ( i do have better things to do ).

Or you can turn off Javascript and hit the "End" key. Alas, there does not seem to be any real-life equivalent to that.

Scotty is yet to invent the warp teleportation theory...

Re: If the Earth were 100 pixels wide

#136

Post by afreak »

fusiongyro wrote: post #127
afreak wrote: post #86

Earlier quoted context omitted.

The amount of energy you'd have to expend to fix Venus would be far more costly than trying to keep Mars warm by using baseboard heaters on every square metre. One of the largest issues facing Venus is that it is effectively a dead planet. Mars is a dead planet too but it's far easier to make it warmer than to cool down Venus so we can live on it. On top of that, Mars has water frozen at its surface and perhaps in li…

I appreciate your taking the time to reply, but I think it's a little soon to be saying never. For one thing, we have spent a lot more time and energy trying to figure out what's going on with Mars than Venus. Though of course Mars is a better prospect today. Frankly, I think the important thing is to have a backup, as it were, and to that end whatever serves will do. But if one backup is nice, two is even better, an…

In the case of Venus, the Soviets had sent several probes (Venera) from the 60s into the mid-80s. When the first probes were sent to land on the surface, it was discovered that the atmospheric pressure induced (about 100x the pressure here on Earth at sea level) was crushing the probes before they even touched down.

It took until 1970 for the Soviets to succeed and the landing device lasted a grand total of a half hour once it had landed on the surface. In fact, it barely survived due to the fact that the parachute broke and it ended up hitting the surface at 60 KM/h. It registered CO2 levels of 97% during its descent.

Venera 9 was similar in concept to the Viking landers and landed five years later, but it managed to last for almost an hour before failing due to the immense heat. The longest any Venusian surface programme by the Soviets was just shy of two hours.

Let's compare this to the Americans' probes to Mars: all of them have managed to out-last their stated mission. We have a rover that was intended to do its job within a 90-day period which instead has defied its masters and instead continued on to this very day.

The reason why I completely discount Venus as a place we'll ever visit or colonise for that matter is because it comes down the old principle that I like to follow: it's easier to bundle up than to bundle down. I can put on layers to keep my body heat in, but I cannot do much without expending energy to cool myself down.

Venus is not a backup.

Re: If the Earth were 100 pixels wide

#137

Post by fusiongyro »

afreak wrote: post #136
fusiongyro wrote: post #127

Earlier quoted context omitted.

I appreciate your taking the time to reply, but I think it's a little soon to be saying never. For one thing, we have spent a lot more time and energy trying to figure out what's going on with Mars than Venus. Though of course Mars is a better prospect today. Frankly, I think the important thing is to have a backup, as it were, and to that end whatever serves will do. But if one backup is nice, two is even better, an…

In the case of Venus, the Soviets had sent several probes (Venera) from the 60s into the mid-80s. When the first probes were sent to land on the surface, it was discovered that the atmospheric pressure induced (about 100x the pressure here on Earth at sea level) was crushing the probes before they even touched down. It took until 1970 for the Soviets to succeed and the landing device lasted a grand total of a half ho…

I can appreciate that it isn't viable today. But looking back on the history of our species, things that seemed useless or even harmful frequently turned out later to be indispensable resources. Sometimes they did turn out to be simply unhelpful and harmful and I can appreciate that this is the current state of knowledge with Venus, and that it isn't especially economically meaningful to hammer on it further at this time. I just don't think it's safe to consider the matter settled for all time.

Re: If the Earth were 100 pixels wide

#138

Post by ajays »

marcosdumay wrote: post #122
austenallred wrote: post #6

This is the first time I've actually been able to comprehend the perspective of distances so big they don't mean much as a number. Thank you.

You can easily build an in 1:2e9 scale replica of the Solar System. You'll just need a 90cm sphere to use as the Sun, some 4-5 km of area do arrange things and a paquimeter for measuring the planets. At this scale, everything is just about as big/small as one can manipulate. Bu you won't be able to place the Voyager in there. For that you'll need a car and a road trip.

Isn't there such a thing in downtown Ithaca?

Re: If the Earth were 100 pixels wide

#139

Post by X-Istence »

sho_hn wrote: post #28
brownbat wrote: post #22

I'd really like to see a few more markers: 1) 3100 px: Farthest humans have been from Earth (Apollo 13, April '70: 400,171 km) 2) 10 px: Gemini 11, farthest from Earth on non-lunar mission (Sept '66: 1,374.1 km) 3) 3 px: Apogee of ISS (farthest a human has traveled for... a while: 424 km) (I'm probably forgetting something, can't find a good list of spaceflights by distance...) Sources: http://en.wikipedia.org/wiki/L…

I think the value of this is in its focus and simplicity. There have been other websites using zooms and/or scrolling to visualize scale differences (e.g. http://scaleofuniverse.com/ ), but this is an elegant statement about just one fact, and I think that's more likely to get the ball rolling in someone's brain and amaze them than inundating them with trivia all at once (but thanks for the trivia just the same :).

Every time I see that page it makes me realise just how small and insignificant we are in the grand scheme of things, and how badly I really want to go exploring everything that is out there.
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