Monday, September 04, 2017

2017 Total Solar Eclipse

Mark Graves of The Oregonian/OregonLive got this shot of the 2017 solar eclipse in Salem, Oregon during totality.

I wanted to try to capture my experience of witnessing the solar eclipse of 2017. My in-laws, wife, and I headed up to Eastern Oregon in order to check out the eclipse. Up until this point, I had never witnessed a total solar eclipse (plenty of partial eclipses, but never a total eclipse). One hears about these things, but never gets a chance to see them, as they usually seem to pass over places like the middle of the Pacific Ocean, or over Antarctica, or other similarly hard place to get to. This was our chance to see the real deal, and it was within relatively easy driving distance of the Bay Area.

My wife planned our trip months prior to the eclipse. It was a good thing too, as all the hotels and campground of eastern Oregon were rapidly scooped up by eclipse fanatics pretty early on. We headed up to Oregon a few days before the eclipse in order to beat the rush. We had heard that Oregon was going to get flooded with something like 1 million visitors, and we didn't want to get stuck in traffic -- at least not on the way up. We stayed in the small town of Sisters, Oregon and took a short day trip up to Madras for the eclipse. My wife, once again, sagely bought a day pass for the Madras airport so we could be in the absolute center of the eclipse's path.

The sun began to get covered by the moon at around 9 to 9:30 AM. Slowly, the disk of the sun was consumed over a long period of time. This is when the solar eclipse glasses were used so we could monitor the eclipse's progress. The daylight got a bit dimmer over the next hour, but it was only in the few seconds before totality that things got really dark and quite odd. To me that was quite a surprise, the difference between 99% and 100% totality is literally the difference of night and day.

To be quite honest, words describing and even professional photos of a total eclipse do not do the phenomena justice. It is an overwhelming experience. The sun disappearing is just part of the experience. Photos can't capture the missing sun, the darkness of the sky, the stars shining in that darkness, and the strange twilight on the ground in the same shot. In the last few moments before totality, it was if someone had turned the sun off with a dimmer switch. It takes about 5 seconds for things to go to black. In that time, the daylight rapidly faded to non-existent, and the sky overhead turned to a night sky dominated by the pure white, diffuse, feathery ring of the sun's corona -- with the sharp black silhouette of the moon in its center.

The ground wasn't completely dark. There was just enough light to navigate the people and things around us, lit by the corona and by the light of the distant hills, sky, and clouds outside of the moon's shadow. There was quite a bit of spontaneous whooping and cheering from the witnessing crowd, including from me. We were able to make out at least one orange solar prominence against the dark edge of the moon's silhouette. We were able to see stars and the planet Venus in particular. We also noticed how cold it had suddenly become. Then, after two minutes of totality, the smallest bead of brilliant white sunlight broke the darkness, and the daylight rapidly returned.

It was a magical, once in a lifetime, experience.

A few observations:

1. As the moon progressively covers the sun, you can definitely notice the temperature dropping. It gets really chilly during totality.

2. Even with the sun mostly covered and showing barely a sliver of the sun, you can still see pretty well, and everything looks pretty much like normal, if dim, daylight. It's only after the sun is completely covered that the sky goes black and everything is clearly 'in the dark.' This makes me think that our eyes can accommodate quite a bit of dimming before we experience everything as being 'dark'. It would've been interesting to document the size changes of everybody's pupils during the hour before the eclipse.

4. After your eyes have adjusted to totality, the first bead of sunlight that signals the end of the eclipse is absurdly bright white.

5. Witnessing a total solar eclipse is like nothing I have ever experienced in my life. Very powerful, very visceral, tying the celestial to our earthbound lives. It is no wonder our ancestors were freaked out by them, and treated them as omens of national disasters.

6. iPhones take crummy, fuzzy pictures of solar eclipses. Don't bother trying.

I've linked a video of the eclipse that covers the beginning and ending of totality. 2017 Eastern Oregon Eclipse

Tuesday, December 22, 2015

Falcon 9 and Blue Origin Booster Landings:Compared and Contrasted

Obviously there is big excitement around the space community today as SpaceX has finally demonstrated a Falcon 9 booster landing during a flight to orbit mission. SpaceX is no stranger to landing boosters, but landing them successfully from an orbital launch has eluded them so far, with two attempts at barge landings turning in less than stellar results. Last night, however, they stuck the landing after lofting the second stage and its Orbcomm satellite payloads into orbit.

Now very technically, SpaceX is not the first company to stick a booster landing after a launch. Very technically, that honor belongs to Blue Origin, who landed their New Shephard booster after a sub-orbital launch on November 23, 2015. What Blue Origin did was pretty impressive. They managed to land a VTVL booster after it had returned from the edge of space (100.5km up), which isn't half bad, and their accomplishment makes sense in their plan for playing in the sub-orbital space tourism market, so kudos to Blue Origin. That said, the booster recovery of Blue Origin and the booster recovery of SpaceX aren't terribly comparable.

The SpaceX booster is about 45 meters long and dwarfs the New Shephard Booster. The New Shephard booster weighs in at about 40 tons, while the Falcon 9 booster starts off at about 460 tons, about an 11:1 weight ratio. New Shephard booster only has to drop back down to its launch site before firing engines. The Falcon 9 has to return to the launch site via a high speed u-turn from somewhere out in the Atlantic, so essentially the Falcon 9 booster has to fly sideways to it's landing location. So comparing the two boosters is a bit like comparing a Cessna to a 747.

A time lapsed photo of the Falcon 9 launch followed by the booster landing.

Monday, July 20, 2015

Happy Moon Landing Day! (Apollo 11 lunar landing: July 20, 1969)

It was 46 years ago today that the Apollo 11 Lunar Excursion Module touched down onto the lunar surface in the Sea of Tranquility. A few hours afterwards, Neil Armstrong became the first human ever to step down onto the surface of another world. Buzz Aldrin followed a few minutes later. In the history of the Earth, only 10 other people have ever had the chance to accomplish that feat. Wouldn't it be something to see humans accomplish great things once again?

If you are interested in the history of the Apollo moon landings and are particularly interested in the nitty gritty details of how the landings played out, be sure to check out the Apollo Lunar Surface Journals, a website that contains pictures, videos, audio recordings, logs, debriefings, and more. It provides a wealth of raw information, and well worth a few dozen hours of perusal.

Wednesday, July 15, 2015

Pluto Painstakingly Probed Perfectly!

First images sent back from the New Horizons spacecraft have given planetary scientists much to think about. Images were first shown during a NASA news conference that was held on July 15th at 3PM EDT. Alan Stern was happy to report that photos of the surface of Pluto seem to match up nicely with the teams predicted models. Vertical cliffs are an indicator that much of the surface of Pluto is comprised of water ice. A thin veneer of Nitrogen indicates that Pluto may possess active cryo-volcanoes or geysers emitting Nitrogen into the local space. These first images are tantalizing, but the real bulk of the images won't be sent back in their entirety for about another year and a half.

The New Horizons spacecraft will now continue on out further into the far reaches of outer space. The team has three Kuiper Belt Objects (essentially small objects about 1 to 2% of the size of Pluto) that are being evaluated as potential targets for a follow-on New Horizons fly-by. Meanwhile, Pluto will never be seen the same after New Horizons' brief but thorough visit.

Tuesday, July 14, 2015

..and now we wait.

So the New Horizons spacecraft passed Pluto and now has begun to send back pictures to the ground team. The transmitter data rate is down to 2000 bits per second, and they can only achieve that by using the spacecrafts two transmitters. The amount of data being sent back is pretty huge, and will take upwards of a year to get all of the data from the fly-by sent down from the spacecraft, although early this evening a few tantalizing images should be available. At this range (approximately 7.5 billion kilometers), it takes a radio signal about 7 hours to get from the Earth to the spacecraft, or about 14 hours for one command to be sent and a response to be returned. (Yikes!)

Monday, July 13, 2015

Fly-By of Pluto Mere Hours Away

The New Horizons Spacecraft is expected to make it's closest approach to Pluto in less than 14 hours from now. Thus the craft's nearly 9 and a half year journey to Pluto will be complete (although the mission itself will continue on past Pluto for some time). A sample of the ashes of Clyde Tombaugh, the discoverer of the (dwarf) planet Pluto, are on board the New Horizons spacecraft, so after 85 years, Clyde and his planet will finally get the chance to meet!

The nearest approach to Pluto will occur at 11:49 UTC on July 14th (7:49 AM Eastern/4:49 AM Pacific Daylight Time). You can follow the progress of the spacecraft at the primary Johns Hopkins mission site or the NASA Pluto site.

Monday, June 29, 2015

CRS-7 News so Far

NASA held a morning news conference to discuss the SpaceX CRS-7 "Anomoly" or "RUD" or explosion, depending on how you want to spin the issue. So far there seems to have been an overpressure event in the second stage's LOX tank -- the exact cause isn't know -- but that seems to be where SpaceX is focusing their attention. The FAA is overseeing the investigation that SpaceX is performing, with NASA assistance as needed. The FAA considers this an "incident" rather than a full up "accident". These are terms that are probably more significant if you speak government-ese.

The other concern was whether or not the ISS was going to be in trouble with the lack of supplies. There may be a bit of a problem with water filters for the water recycler (the filters aren't worn out, but they are getting rather full of stuff), but other than that, there is enough food and supplies until the Japanese, Russian, or Cygnus supply spacecrafts can get there.