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Cassini’s mission is complete

This morning, Cassini plunged too deep into Saturn’s atmosphere to survive.  Nearly an hour and a half later, the signal being received through the Deep Space Network’s biggest dish at Canberra terminated.  It was the end to a wildly successful twenty year jouney, thirteen years of it in orbit around Saturn.

This is Cassini’s last picture, taken through three filters and assembled into a true-color image.  It shows the place on Saturn where the spacecraft would later enter the atmosphere and burn up.  Cassini entered in daylight, but this site was still in night when the image was taken, lit only by ringshine.  It was a long and glorious journey; now we have to look to what may come next in exploration of the outer solar system….

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The Great American Eclipse

I haven’t posted in a while, because I’ve been traveling.  And I bet you can guess what I was going to see!  We loaded up the kids and my telescopes, met my in-laws, and took off on a road trip across South Dakota and into Wyoming, with the ultimate aim of basking briefly in the shadow of the Moon.  I’m finally back, so I’m gonna share my pictures with you!  Here’s sort of a filmstrip of the eclipse, as seen from the pleasant little town of Glenrock, Wyoming:

The Sun, before eclipse, as seen through my Orion SpaceProbe 130ST, and shot through the 25mm eyepiece with a cellphone.  Remember: if using a telescope to view the Sun, never look through it unless it has a full-aperture solar filter on.  That’s a filter that goes over the big open end, not the eyepiece.  Put a filter on the eyepiece, and you’ll just burn a hole right through it.

And here’s a similar shot by my husband’s cellphone, through the 25mm eyepiece of my Skywatcher 8 collapsible Dobsonian. (Yes, I know I brought a couple of Newtonians to look at the Sun — they’re not the best suited for the job. But they were great for looking at stars that evening, and they did do a pretty good job of working for us at the eclipse!)

First contact (well, shortly thereafter) through the SpaceProbe 130ST. 130 refers to the 130mm aperture (it’s a Newtonian) and ST refers to the fact that it’s got a short tube (which makes it more portable and improves the field of view — these pictures have all been cropped).

Same view through the 8 inch collapsible Dob. The filter on that one is a different type, so we get a yellower Sun.

Now, if you don’t have a filter but have an inexpensive refractor (or a pair of binoculars), you can use them for projection. I’m using a Galileoscope here — and as it happens, this is basically how Galileo used his telescope to discover sunspots. Many solar telescopes still use this method, including the McMath-Pierce Solar Telescope, because it removes none of the wavelengths of light that they may wish to study.

The Moon is advancing towards those nice sunspots in the middle….

The eclipse shades are pointing out something interesting we noticed. I hung a makeshift cardboard shade around the little refractor telescope so we’d be able to see the projected image more clearly, and there was a tiny hole in it, which was projecting a little crescent Sun of its own — but in the opposite direction to that produced by the refractor’s lenses.

By now, it was getting really easy to see the eclipsing Sun even with unaided (but properly filtered!) eyeballs.

Getting thinner — that last sunspot group won’t be visible for much longer!

Here I’m holding the box for my big telescope’s solar filter perhaps a bit too close to the telescope; it’s remarkable how bright the projected image gets as it gets closer. You wouldn’t want to put your eye there.

Another fun thing you can do with the projection method — hold the crescent Sun in the palm of your hand! Also, you might notice how the background is looking kind of odd. Washed out a bit, as if it were evening. But the shadows are short. By this time, it was considerably cooler and darker, and the insects were coming out to feed, thinking it was close to sunset.

That crescent is razor thin now! I’ve set the box on the ground to get the crescent stretched as far across it as I could. The ground is even darker now.

Meanwhile, I had my Nikon Coolpix mounted piggyback on my 130mm Newtonian. That one’s got an equatorial mount, making it much easier to track the Sun. It’s wearing its own little solar filter at this point, and zoomed in to the max. To avoid hand-shake, I took time-delay shots.

The horns of the crescent retreat surprisingly rapidly at this point.

I’ve cropped in a bit more here; the Sun’s photosphere is barely visible.

And, filters off!!!! My Nikon had the best field of view of all the magnified instruments, so this is the one that was able to catch the outermost parts of the corona. Down and to the left, that’s Regulus, a bright winter star that was plainly visible during the eclipse.

Here’s the view from the 130mm telescope; you can make out a bit more detail. It looked much better with the naked eye; it’s tough to get the cell phone cameras to get the right exposure for this.

And here’s with the 8 incher. There’s quite a bit of detail in the polar regions of the Sun, where you can make out streamers in the corona.

And the diamond ring appears! This heralds the end of totality, as the photosphere peeps over the Moon’s limb. At the right, you can just make out a solar prominence. We’d gotten a much better look earlier from another stargazer’s awesome h-alpha setup.

And with that, it’s time to put the filters back on.

About this time, excited eclipse viewers noticed an extra treat high above — the thin clouds that had started to gather were hosting a sun halo.

Little tip: never try to take eclipse pictures with a handheld camera, especially AFTER totality, when you’re still shaking from the adrenalin. 😉

And this is the last shot I got. Some folks stuck around for fourth contact, but my father-in-law had an excellent pot roast and a bottle of wine ready to celebrate by this time, so this was the end for me. End of a day I will never forget.

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Ariane V flies again!

After the long general strike in French Guiana halted launch operations, a deal has been reached and Arianespace is eagerly resuming flights.  Today, Ariane V returned to service, placing the SGDC spacecraft into orbit for Brazil, and Koreasat 7 for South Korea.  Both vehicles are commsats bound for geosynchronous orbit, the type of mission that has long been Ariane V’s bread and butter.  This is the 78th consecutive successful mission for Ariane V.

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Cape Canaveral’s got a brand new zipline!

Cape Canaveral has a brand new zipline!  But alas, it is not available to tourists.  Not unless you’re a really, really, really rich tourist and have managed to book a ride on a CST-100 Starliner!

One of the requirements for a man-rated launch vehicle is some way to quickly escape the vehicle in case it’s about to go kablooie.  Mercury and Gemini had no escape system, other than the vehicle’s own launch abort system (which in the case of Gemini, consisted of ejection seats that were believed to be nearly 100% certain to be fatal if used on the pad, due to the sidewise orientation of the vehicle before launch), other than riding the elevator back down and hoping really really hard.  The first pad escape system that would save crews not yet in the vehicle or allow crews to safely egress during an abort was a super-fast elevator on the Saturn V launch umbilical tower that delivered the crews to a blockhouse under the pad, where they could survive for some time, long enough anyway for whatever was going on above to burn itself out and the fumes to dissipate.  On Shuttle, things got a little spunkier, with the addition of the slidewire baskets that would let crews slide rapidly to safety — which would consist of several armored transports  parked nearby, which they’d jump into and drive away as quickly as possible.

The slidewires were deemed more effective (and more reliable, being powered entirely by gravity) than the Apollo elevator, and so it is perhaps no surprise that ULA, in building a system to meet Boeing and NASA’s specifications, is opting for a wire again.  Only instead of a set of baskets that can carry several crew apiece, this one is a zipline with a couple dozen single-person seats, enough to evacuate the crew and ground support personnel, and because they are individual, you just jump in it and go — you don’t have to wait.

But I gotta admit, part of me really likes the fact that this system isn’t being built by some stodgy old defense contractor, like most of the system.  No, this one’s being built by a company that specializes in ziplines — Terra-Nova LLC.  And it’s pretty much exactly the same system they build for tourist use at locations around the world.  They’ve got extensive experience; from their perspective, this was actually a very small job….

Wheeeeeeeeee!

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SpaceX has reflown a booster!

The first reflown Falcon 9 first stage core has completed its second mission, and been recovered successfully on a barge at sea.  They also apparently recovered half of the payload fairing, which I didn’t know they were even thinking about attempting.  The upper stage went on to deliver SES-10 to the correct geosynchronous transfer orbit.

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Vote!

Tomorrow, November 8, is Election Day here in the US.  And with that in mind, I have just a few things to say on the subject of voting:

  1. It is important to vote.  This is the most fundamental way in which your voice can be heard, and people have suffered, bled, and died for the right to vote — don’t squander it.
  2. It’s your vote.  Only you get to decide what to do with it.
  3. You can vote for anybody you want.  There may be some restrictions to their eligibility to actually serve, but you can cast your vote for absolutely anybody.
  4. There’s usually more than one thing on the ballot; I know most of the attention has been on the REALLY BIG ONE, but the other ones are important too.  You might have school board members, sheriffs, judges, county commissioners, soil and water conservation district supervisors — and all of these people can have a very immediate impact on your life.  Moreso than a senator, governor, or even the President.  They’re worth taking seriously.
  5. If an incumbent is running unopposed, you can still vote for them.  You can also vote against them, even if you have to write someone in.
  6. Even if you write in absurd candidates, remember, even those votes are counted.  Sure, Donald Duck is never going to be President, but while it wouldn’t change the outcome, enough people voting for absurd candidates could cost a President the popular vote.  That sends a powerful message.  Yes, even Donald Duck votes count for something.
  7. You can vote for a candidate — and you can also vote against them.  There’s more than one way to vote against them: you can vote for an absurd write-in (“none of the above” has a certain appeal, I have to admit), or you can vote for the candidate you think has the best shot of defeating them.  Both are valid strategies; neither is a waste.
  8. Even if you don’t vote, you still get to complain about the outcome.  There’s this thing called the First Amendment that pretty much guarantees that, at least in the United States.  😉  And hey, statistically speaking, on Wednesday we’ll probably all come together as a nation to loathe whoever we ended up electing.
  9. And last but not least, the only wasted vote is a vote that isn’t cast.

 

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Vandenberg Wildfire Status: 70% Contained, One Fatality

A sad update on the Vandenberg wildfire: although crews as of this morning had the fire 70% contained, it has now claimed its first victim.  Well, not directly.  A firefighter responding to the fire was killed when his water truck overturned on the way in to fight the fire.  The Santa Ana winds fanning the fire also make it more difficult for top-heavy firefighting equipment to navigate the dangerous roads in the area.  Keep his family in your thoughts; the firefighters who tackle wildfires are a special breed, who take extra risks the rest of us would never contemplate.

Crews are making significant progress fighting the fire, however, and off-base evacuation orders have now been lifted.  The base is expected to soon return to normal operations.  What everybody really needs down there, though, is some rain.  The longstanding Southern California drought has greatly elevated the fire risks.

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