Only the shadow knows


Next Monday (2/2) is Groundhog Day! Halfway through Winter. SpaceX gets another one billion dollars in investments for newly proposed 4,000 satellite broadband plan. Venus and Mars still dominate the western sky right after sunset but over in the East, the king of the planets, Jupiter rises just after sunset and is visible all night. Saturn rises around 3am and is well up in the southeast by 6am, an easy target for pre-dawn sky observers.

January 26, 2015


[Dave Heller] Here’s an invitation to participate in an annual experiment to alter space and time with Derrick Pitts, chief astronomer at the Franklin Institute. Derrick, the invitation is for one week from today. The space is set some 200 miles to the west; now the experiment: shortening the time to the advent of spring.

[Derrick Pitts] And it’s amazing to think that we’ve discovered that the way of shortening time through the lowly groundhog.

Not so lowly if it works.

It’s not so lowly if it turns out to work, yes indeed, next Monday actually is the big day we’ve all been waiting for. Yes that’s right folks, Groundhog Day.

Oh, they’re showing that movie again?

Actually it’s the real thing. Punxsutawney Phil will make his appearance early next Monday morning. And the question of whether or not we can shorten the time is determined by whether or not he can see his shadow.

Only the shadow.

Only the shadow knows. But, actually, he’s just a fixture on the large stage of the astronomical mechanics of the universe. As it turns out, the Earth will have reached a point in its orbit around the sun where we are halfway between the Winter Solstice and the Vernal Equinox. So Groundhog Day is what we call a cross-quarter day, that point at which we’re halfway through the current season. So, as far as I’m concerned, I think of this as oh my goodness, here we are, headed toward spring. It’s coming any day now! And the groundhog just helps us confirm we’re on the way.

  • Bill Murray and Punxsutawney Phil go for a ride in the movie Groundhog Day.

I like it. Derrick, we’ve spoken often about SpaceX, now they’re venturing into yet another new field.

Yes indeed they are. And it is connected to the SpaceX launch capability, but it’s a different application all together. In this case, what Elon Musk plans to do is launch 4,000 broadband communicating satellites that will be used to provide low-cost internet access all over the world. And the idea here is that it will be low cost internet access and for anyone who can access the network to be able to communicate on the worldwide web.

How would it roll out?

Well the way it would roll out is that he has the launch capability, so all he has to do is have the satellites built and then he can actually put the satellites into orbit so that anybody will be able to use this network, and thereby provide unlimited access all around the world.

And who’s betting on this?

Well that’s the interesting part about this. He’s doing this with investment funding provided by two groups: Fidelity Fund and Google. Now it may not be surprising that it’s Google, it may be a little bit more surprising that it’s Fidelity Fund. But even more surprising than those two things is that it’s actually one billion dollars of investment.

Not chump change.

No, not at all. If it were 100 million dollars or 200 million dollars, you could say, well, they’re going to take a chance on something. But in this case, with a billion dollars between them, they feel pretty confident that SpaceX is the kind of company that can make something like this happen. Of course they’re going to be looking at the track record of Elon Musk and his Tesla motors, as well as his plans for a high speed travel carter between San Francisco and Los Angeles called the Hyper Loop, and also they have seen how successful he is in his space exploration ventures. So they feel pretty confident that a billion dollars on the line will be a safe bet, both for Google for communication purposes and possibly Fidelity for recouping their investment and gaining some profit too.

  • Elon Musk, left, CEO and CTO of SpaceX, mingles with invited guests inside the SpaceX Dragon V2 spaceship at the headquarters on Thursday, May 29, 2014, in Hawthorne, Calif. SpaceX, which has flown unmanned cargo capsules to the International Space Station, unveiled the new spacecraft Thursday designed to ferry astronauts to low-Earth orbit. (AP Photo/Jae C. Hong)

I heard you mention some four thousand satellites. Put that in context: Are we at the point where we need an air traffic controller to keep all these satellites from banging into each other? And four thousand sounds like a big number — how many satellites are there overhead at this junction?

You know Dave, that’s actually a really, really great question. And when I looked at this too, at first I was excited about the idea that broadband would be provided to so many people around the world. And that’s a great thing. But when we think about the number of satellites — four thousand — that’s a large addition to what’s already up there. There are tens of thousands of objects in orbit around the planet; you know, a lot of it is useless space junk, of you will — leftover rocket boosters and defunct satellites and all sorts of things like that. And there actually is some serious concern that the number that’s already there and a growing number in addition to what’s already there is going to cause serious problems for space exploration and just access to low Earth orbit because of this enormous cloud of material. These satellites that are still hanging around in space long after their useful lifetime. These objects pose a threat to all of the active satellites because one simple fact — if there’s a collision between two, they tend to create a large cloud of debris, travelling along at a very high rate of speed, upwards of 15 to 20,000 miles per hour. So that makes every one of these things potentially like bullets that could destroy other spacecraft. So it does pose a great threat, and the idea of adding more satellites to this number is really something that should be considered as whether it’s going to help the problem in some way, or make the problem worse.

Now let’s peer past the man-made satellites — what’s available to be seen in the night sky this week?

There’s really a lot of great stuff. If we start out with the easily observable, we can start out with Venus and Mars in the southwestern sky, not long after sunset. Just as soon as the sky’s getting dark we can begin to pick out bright Venus. And just above it, just a tiny bit to the left, we can see the small but bright and stable Mars, as it’s easy to locate. Now just about an hour later — 6:30 in the evening over on the eastern side of the sky, Jupiter makes its way over the eastern horizon and is visible all night long. So if you were looking to see the king of the planets, you can see Jupiter without any problem at all as long as the sky’s clear. If you’re an early morning observer — predawn, you’re out at 6:00 in the morning heading to work while it’s still dark — you’ll find Saturn way up in the southeastern sky at that time, and that’s also great view and looks really good in binoculars.

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