Musings on optics, physics, astronomy, technology and life

Posts tagged ‘solar system’

Just a few days to go…

Let the record show that, nearly a year ago, I predicted the hype over the Great Eclipse of 2017. I just thought it might start a little sooner than the week before the big event. However, we Americans have notoriously short attention spans. Eclipse on the 21st of August? By the 31st of August, it will have been completely forgotten, and everyone will be focused on Britain’s royal family.

I know that, come next Monday, I’m not going to be in the path of totality. Yeah, I wish I could. However, this past weekend my car decided that it could eat its own radiator and alternator for Sunday brunch. I paid the $773 bill, but I won’t have spare change until next Friday. I can do a lot of things, but changing the alignment of the Sun, Earth, and Moon to suit my bank account isn’t one of them.

Once before, I was in the path of totality. You may recall the eclipse of July 11, 1991 — it passed right over Mauna Kea. That summer I had an internship at Kitt Peak National Observatory in Tucson, but I arranged to take a trip with three undergraduate and graduate students from the University of Arizona down to Mazatlán, Mexico, which is about as far south as the tip of Baja California, but on the mainland instead of the peninsula. Unfortunately for our traveling quartet, while the tip of Baja California had a grand view, Mazatlán seemed to be the only major Mexican city that was completely overcast. The thick clouds did get very dark for five and a half minutes around noon … but, yeah, it wasn’t the same as an actual view.

And since the closest part of the path of totality to my current Maryland residence is in South Carolina, which seems to have a pretty good chance of clouds and/or rain … yeah, I think I’m better off staying put and waiting for April 8, 2024.

Anyhow … before the eclipse hits Monday, I urge you to educate yourself about eclipse-watching safety, first and foremost … and also what to expect wherever you are, and where to find the cool pictures online. Here’s my curated list of links:

  • The two sites I mentioned last year, and, are still up and running.
  • The two major U.S. magazines for amateur astronomy, Sky & Telescope and Astronomy, each have a comprehensive guide to solar-eclipse viewing, eclipse science, and eye safety.
  • The American Astronomical Society (AAS), an organization primarily for professional astronomers, nevertheless has assembled an eclipse site for the general public.
  • Not to be outdone, NASA has another pretty comprehensive eclipse portal, and my local friendly space center’s visitors’ center will have programming for the masses.
  • One of the DC-area TV stations advises viewers on procuring those crucial solar-eclipse glasses.
  • Plug your zip code into this page to see what percentage of the Sun’s disk will be covered in your area.
  • Wondering whether the weather will give you the same totality-blocking heartbreak that I felt in 1991? My friend at the Associated Press summarizes the forecasts.
  • Somebody who knows how to use GIS software has figured out the eclipse traffic choke points. I like the notion of a “driveshed,” which is to roads what watersheds are to bodies of water, and wonder about its applicability to other events.
  • More solar-viewing safety tips. (I remember that my father brought home some welding glass from his workplace so that I could view a partial solar eclipse when I was a youngster. I don’t know the “number” of that glass, but it must have worked, because I don’t have eye damage from that experience.)
  • Courtesy of Newsweek and Mother Jones, a handy guide to eclipse photography.
  • Finally, if you want to watch the total eclipse from the comfort and safety of your television or computer, here’s a guide to that experience.

Remember, SAFETY FIRST!!!


Two weeks later

It’s been two weeks since a “freaky space rock” blasted out of the sky above Chelyabinsk, Russia. At the time, the worldwide press breathlessly reported the extent of the amateur video footage and the ground-level damage and then moved on to other flavors of the moment. Meanwhile, what have we learned about our cosmic visitor?

A week after the event, Sky & Telescope reporters blogged about the composition and trajectory of the Chelyabinsk meteoroid. The recovered fragments are “ordinary chondrites,” the most common type of stony meteorites. These ordinary chondrites do contain flecks of metals, but also lots of silicates, as opposed to iron meteorites, which really are chunks of iron. The space rock was moving in a completely different direction from the asteroid that nearly missed the Earth the same day, so the events were unrelated, as much as our pattern-seeking human brains would like to deny.

S&T also reported that a scientist at the University of Western Ontario calculated that the near-Earth object (NEO) was cruising at 20 km/s when it hit the atmosphere. The “infrasound” detectors that are supposed to enforce the nuclear test-ban treaty picked up the blast waves — equal to about 30 Hiroshima bombs — from as far away as Antarctica.

Scientists suspect that the space rock came from (or was) an Apollo asteroid, a specific class of minor planets that cross Earth’s orbit. So, yeah, this should really point out the need to keep watch on the other Earth-crossers that may be whizzing by. The University of Hawaii is developing a “last-alert system” to complement PanSTARRS. And, as Chelyabinsk cleans up, local officials are figuring out how to market the newly famous city as a hot tourist destination. (It even has a travel agency called Sputnik!)

“Freaky space rock Friday”

In my humble opinion, today deserves the moniker bestowed upon it by Brian Vastag of the Washington Post: “Freaky space rock Friday.” We’ve got not one, but two major news stories about the solar system: the close passage of the asteroid 2012 DA14, discovered almost one year ago, and the surprise fireball that blasted out of the sky above Russia’s Ural Mountains this morning.

I’ve been as amazed as everyone else at the amateur “dash-cam” footage of the meteor making its way around the Web, but I’ve got to get some other (non-solar-system) work done this afternoon as well. In addition to Brian Vastag’s live blog, you can check out my retweets and repostings on my own Facebook and Twitter accounts (see links in the right column). Or you can follow astronomers such as Neil deGrasse Tyson (@neiltyson) and Jonathan McDowell (@planet4589) on Twitter.

More later, as I have time….