Sucker Holes, Media Hype, and Observational Reality

Be Realistic about Observing

One of the truisms in amateur astronomy is that the minute something exciting is predicted to occur in the sky, the sky immediately clouds up.   This is true especially if there’s an especially juicy coronal mass ejection inciting some space weather in Earth’s close neighborhood.  Or, perhaps an occultation of a star by the Moon. As soon as the news gets out, the clouds start to gather.

This happened to me on October 8th, when the space weather forecast showed a good chance of seeing aurorae even at the mid-latitudes. I mentioned this as part of a talk I gave onboard a cruise ship that day (I do astronomy enrichment presentations for the Smithsonian and Celebrity Cruise Lines) and of course it clouded up that night.  But, we persevered, and eventually a sucker hole did open in the clouds that revealed some of the sky, and we saw a gorgeous greenish display to the north, complete with spiky formations that came and went.

Another case in point has been the media hype for the Orionid Meteor shower that was supposed to deliver dozens or more meteors per hour.  The news media picked up on this right away, and I saw at least one  headline about “spotting a stunning meteor shower” from a news organization that used to have a qualified science writer on its staff but now just rewrites from a press release, spices it up, and then publishes hypey stuff that they think will grab people’s attention. (Yes, CNN, I’m talking about you…)

The press release I got from a reputable observatory mentioned that it might be possible to see up t0 25 meteors per hour.  No promises, just a possibility. No flashy graphics about “dazzling” sights… And, reports I’ve seen from actual observers indicate that the counts have been a bit less than normal.

This is the sort of thing that really ought to give the media a bad name for over-hyping.  A competent science writer would have been able express the story much more clearly for readers/viewers and given a more realistic view of what the shower might look like.

The reality of observational astronomy is that sometimes something can be quite spectacular, and sometimes it just isn’t. Astronomers’ models can only go so far in predicting how good a meteor shower, for example, will look. There are a lot of other factors that influence your observational experience… including clouds.

The best thing to do is get out there and observe… there are some gorgeous skies coming our way over the next few months, so be ready for them! Cherish each meteor, search out the planets, check out the nebulae, and never stop looking for the wonders to be seen in the night-time sky!

 

Crystalline Entities Found in Distant Solar System

Herschel Discovers Cometary Crystals around Beta Pictoris

We all know about comets in our own solar system. They’re conglomerates of ices mixed with dust and rock. As they get close to the Sun their gases sublimate, the dust is freed and that action creates dust and plasma tails streaming out behind the comet.  Astronomers see comets as repositories of information (in the form of those ices and dust particles) about conditions in the early solar system, since those materials have survived until this time. In particular, comets often contain materials that formed close to the Sun in the early history of the solar system, but then were somehow transported out to colder regions where comets seem to thrive.

This infrared view of the Beta Pictoris solar system, was obtained by ESO’s 3.6-meter telescope and the NACO instrument on one of the 8.2-meter units of ESO’s Very Large Telescope (inner region), and then subtracting the overpowering glare of the central star. The image shows a planet orbiting at roughly the same distance from Beta Pictoris as Saturn is from our own Sun, and a prominent dust disc in the outer reaches of the system. Credits: ESO/A-M. Lagrange et al.

So, it’s rather cool that astronomers have now found cometary particles  in another solar system, the young star Beta Pictoris. The European Space Agency’s Herschel space telescope detected pristine materials in the dust disk surrounding this star. Those materials match the makeup of comets in our own solar system.

Beta Pictoris hosts a gas giant planet, in addition to a dusty debris disk that will likely spawn the formation of some icy bodies similar to the worldlets that astronomers are finding in our own Kuiper Belt.

So, what’s the material made of that Herschel found? First, the mineral olivine is present in the disk around Beta Pic.  Olivine forms in protoplanetary disk material close to newly formed stars.  In our solar system we find it in asteroids and comets, and of course it’s found on Earth, too.

The data collected by the Herschel telescope allowed astronomers to calculate that the olivine crystals in the Beta Pic disk make up about 4% of the total mass of the dust found in a region that lies between 15 to 45 astronomical units from the star.  In our solar system, that extends from well beyond the orbit of Saturn out beyond the inner limit of the Kuiper Belt. The 4% number is quite similar to such solar system comets as 17P/Holmes and 73P Schwassmann-Wachmann 3.

Astronomers concluded that the olivine was originally bound up inside comets and released into space by collisions between the icy objects.  And, since since olivine can only crystallize  at a distance of not more than 10 astronomical units of the central star, finding it in a cold debris disc means that it must have been transported from the inner region of the system out to colder areas. A process called “radial mixing” could help push materials out away from the central star, and that could explain how the olivine crystals made it to the deep freeze of the Beta Pic system.  Want to read more about this find? Check out ESA’s Herschel Web page for the full story.

  Get Your Stargazing On for October!

This month’s edition of “Our Night Sky”, the star gazing video I produce for AstroCast.tv is now up for your viewing pleasure!  Check it out!