Mars is becoming visible again at long last! Here's a picture from the lovely clear night of Saturday 14th January 2012. Picture taken about 00:30 UT 15 Jan 2012, via a DBK colour camera taking 30 seconds worth of 30 frames per sec at 1/109 second exposure, a 2x Barlow lens, on the 20" scope, masked down to 8". 450 pictures were chosen and stacked, sharpened, and a tweak was made to the blue and green channels to compensate for the difference in focus between these colours. Well that's what I did. I'm amazed how much detail I got given the conditions and fact that Mars is tiny! It is a mere 10.2 arc seconds across, or about 180 x smaller in angular extent than the moon. It is half the diameter of earth, 4200 miles, at a distance of about 83 million miles away. You can see Syrtis Major on the left, the large Hellas basin above it, which is near the south pole. Mare Erythraeum is the dark patch at top, the light gap at top right is Chryse, followed by Mare Acidalia. The large area at centre is Arabia Terra. Below Syrtis Major, is Utopia (just at edge), Boreo Syrtis, Protonilus and then a stretching dark finger along the bottom right, Deuteronilus. The light area at bottom right is Vastitas Borealis (North at bottom).
A double quasar... Whatever next! I can't work out why it is blue.
This is not just an 18th magnitude dot. This 'dot' has a red shift of 3.21. That means it is currently 21.6 billion light years away, but it appears in our past 11.7 billion light years away. That's totally messed up when you can't even say how far away it is. It takes far away things to another level. It is a Quasar, a galaxy with a central super massive black hole jet pointing straight at us. I can't express how bright this thing is other than to say that it has an absolute magnitude of -30.0. OK, well I'll have a go. Hang on, I'll get my calculator out... If the quasar was at a distance of, say, the Pleiades star cluster is from Earth, it would appear nine times brighter than the Sun is to us on Earth (caveat: that's probably not an appropriate distance for the calculation). Our universe is only 13.7 billion years old and you're looking back across most of that time, to a time when not only the Earth didn't exist, but the Sun also didn't even exist!
Mars is becoming visible again at long last! Here's a picture from the lovely clear night of Saturday 14th January 2012. Picture taken about 00:30 UT 15 Jan 2012, via a DBK colour camera taking 30 seconds worth of 30 frames per sec at 1/109 second exposure, a 2x Barlow lens, on the 20" scope, masked down to 8". 450 pictures were chosen and stacked, sharpened, and a tweak was made to the blue and green channels to compensate for the difference in focus between these colours. Well that's what I did. I'm amazed how much detail I got given the conditions and fact that Mars is tiny! It is a mere 10.2 arc seconds across, or about 180 x smaller in angular extent than the moon. It is half the diameter of earth, 4200 miles, at a distance of about 83 million miles away. You can see Syrtis Major on the left, the large Hellas basin above it, which is near the south pole. Mare Erythraeum is the dark patch at top, the light gap at top right is Chryse, followed by Mare Acidalia. The large area at centre is Arabia Terra. Below Syrtis Major, is Utopia (just at edge), Boreo Syrtis, Protonilus and then a stretching dark finger along the bottom right, Deuteronilus. The light area at bottom right is Vastitas Borealis (North at bottom).