Measuring The Sky (One-Minute Astronomer)

The Basics

• Astronomers measure angular separation of objects in degrees. There are 360 degrees in a circle. And the angular separation of any point on the horizon and the point directly overhead (the zenith) is 90 degrees. Halfway from the zenith to the horizon is 45 degrees. So far, so good.

• Smaller angles are a little trickier. But your hands and fingers are a remarkably accurate (and convenient) measuring tool. When you hold your hand at arm’s length, you can estimate angles like this:

- Stretch your thumb and little finger as far from each other as you can. The span from tip to tip is about 25 degrees
- Do the same with your index finger and little finger. The span is 15 degrees
- Clench your fist at arms length, and hold it with the back of your hand facing you. The width is 10 degrees
- Hold your three middle fingers together; they span about 5 degrees
- The width of your little finger at arms length is 1 degree.

A Deeper Look

• Now let’s go smaller. When you look through a telescope, you see a field of view of 1 degree or less… a very small slice of sky.

• Astronomers measure angles smaller than 1 degree in arcminutes, or “minutes of arc”. There are 60 arcminutes in one degree, so 1 arcminute is 1/60 degree. The symbol for arcminutes is ‘. So the full Moon, for example, is about 30′ (thirty arcminutes) across. Coincidentally, so is the Sun.

• Each arcminute is divided into 60 arcseconds, or “seconds of arc”. So 1 arcsecond is 1/60 arcminute and 1/3600 degree. The symbol for arcseconds is “. The face of Jupiter, which you can see this summer, is about 50″ across. The two components of the double star alpha Herculi are 4.6″ apart. A good optical telescope in steady skies can resolve down to about 1″ (one arcsecond).

Source:Visit  One-Minute Astronomer

Centaur vuurpyl laat die mense reg oor Suid Afrika en Europa wonder (UFO?)

Photo: Federico and Chiara Bellini of Bodio Lomnago, Italy.

Sondagaand het `n klomp sterrekykers na hulle kameras gegryp en hierdie vreemde verskynsel afgeneem.

UFO het die mense op OFM die plaaslike radiostasie in Bloemfontein gesê. Die kenners het natuurlik met die antwoord gekom:

Gaan loer gerus by hierdie webwerwe wat werklik gebeur het. Ongelooflik.

`n Plaaslike webwerf met sekerlik die beste foto's: Klik hier

Ook by Spaceweather kan jy gaan loer: Klik hier  en beweeg af op die blad

Prof Matie Hoffman van die Fisika Departement by die UV gesels Donderdagaand  om 20:30 met Hennie Maas op Sterre en Planete oor die verskynsel.

Luister Sterre en Planete op RSG

Luister gerus vanaand na Sterre en Planete op RSG
(Elke Donderdagaand om 20:30)

Medewerkers reg oor die land gaan vir Hennie Maas met die program help, na die afsterwe van Louis Barendse.

Prof. Matie Hoffman van die Fisika Departement aan die UV gaan ook vorentoe sy beurt kry.

Vanaand is `n ou bekende in die sterrekunde-omgewing, Willie Koorts van SAAO, aan die beurt.

Inligting oor die uitsending vanaand:

* Gesels oor die LCROSS-sateliet wat in beheerde omstandighede met die maan gebots het in `n soektog na water.

* Luister ook na die liedjie wat die projekleier oor die projek en die water op die maan geskryf het.

* SALT se oogoperasie word bespreek. Baie interessant hoe die 90 ton monster werk.

* Ook inligting oor die Galilean Nights van 22- 24 Oktober .
Webtuiste: http://www.galileannights.org/

Die praatjie is ook op die web beskikbaar om na te luister of af te laai by hulle potgooi-afdeling of die klankargief

• Gaan direk na Sterre en Planete en luister of laai af
  

Groete

Hannes Pieterse

Astronomy Night At The White House

Wow, that’s quite a star lineup! I wish I could’ve been there too. Maybe next year…
And the quote of the night from the President, who said this in response to a young girl who was 14 when she discovered a supernova, and a high school sophomore who found a rare type of pulsar:

NASA’s equipment is some pretty powerful stuff. But astronomy also depends on the curiosity and contribution of amateur astronomers. [...] If they can discover something great, so can any of you other students who are here tonight. All you need is a passion for science.

Damn straight. And awesome.

• Video of event on You Tube

Source:  Blog / Bad Astronomy
October 9th, 2009

Foto van die teiken

Kliek op foto om te vergroot.

Hier is `n voorstelling van die botsing.

• Klik hier
  

Watch Nasa bomb the moon

The LCROSS shepherding spacecraft attached to the Centaur upper stage. Credit: NASA

Seth Borenstein

Washington - Nasa will throw a one-two punch at the big old moon Friday and the whole world will have ringside seats for the lunar dust-up.

Nasa will send a used-up spacecraft slamming into the moon's south pole to kick up a massive plume of lunar dirt and then scour it to see if there's any water or ice spraying up.

The idea is to confirm the theory that water - a key resource if people are going to go back to the moon - is hidden below the barren moonscape.

The crashing spaceship was launched in June along with an orbiter that is now mapping the lunar surface.

LCROSS - short for Lunar Crater Observation and Sensing Satellite and pronounced L-Cross - is on a collision course with the moon, attached to an empty 2.2-ton rocket that helped get the probe off the ground.

Thursday evening, about 10 hours before smashing into the moon, LCROSS and its empty rocket will separate.

Read more...

Another read more...

• A live NASA TV Broadcast is planned for the LCROSS impacts starting at 6:15 a.m. EDT/3:15 a.m. PDT, Oct. 9, on NASA TV and www.nasa.gov/ntv. 
  
  
• Where and how to observe the LCROSS impacts
  (Only visible in the USA)
  
  
• Observations and Impact Timing

'n Nuwe ring vir 'n ou Bekende....!

Die Spinnekop in die (Magellaanse) Wolk

Kyk net hoe die Tarantula-newel kan lyk as 'n mens die regte teleskoop het - en dit nie eers 'n ruimte-teleskoop nie...!

• Lees meer en loer...
  

Op pad terug na sy nes!

• Nog foto's van pendeltuig Discovery op pad na Kennedy-ruimtesentrum in Florida
  
• Loer hier hoe word die pendeltuig op die Boeing gelaai.
  

Bron: Spaceflight Now

Space Shuttle Flushes the Toilet for All the World To See

Shuttle with water dump. Copyright Clair Perry 

Source:  www.universetoday.com

This picture is from last week; September 9, 2009 to be exact, but I still wanted to share it. I just got in touch with photographer Clair Perry from Prince Edward Island, Canada to get his permission to post the image. No, this is not a comet. Pictured is space shuttle Discovery executing a water dump. The shuttle needed to get rid of excess waste water before landing the next day, and jettisoned it overboard via the waste water dump line, creating a spectacular visual effect as sunlight hit the spraying water. This dump occurred just as the shuttle was flying over North America last week, and lots of people witnessed this "toilet flush." Some reports indicated it was "pristine" water (the shuttle fuel cells' by-product is water) and other reports said it was "waste water and urine" (the Bad Astronomer called it Constellation Urion). Whatever, it was pretty. NASA said this was an unusually large dump, about 150 pounds (68 kg), because new regulations say no shuttle water dumps can take place while docked to the ISS, so as not to contaminate the outdoor experiments on the Kibo lab.

See below for the spectacular entire image, which also includes the nearby ISS creating a streak in the sky. Thanks to Clair Perry for sharing his images.

• Read more and see whole image