Well, no, it’s been increasing 0.05 percent per decade since the 1970s. Before that we don’t know because you really need satellites to measure with that precision.

I’m not saying it’s driving GW, but there *is* a small increase. If it has been going on through the 20th century, then it could be a factor if only as something to exacerbate AGW.

I’m just sayin’.

I showed Mars to a friend’s wife a few years back during a previous opposition. She sniffed and said, “I thought I’d be able to see the storms.” Mind you, I didn’t force this. She *asked* to see it, having heard about it on the news. I dragged the scope (a 16.5″ Dobsonian) out just to show her.

I’ve never shown off anything through the scope since.

[[This indicates to me that Jupiter must also be warming up because more storms indicate warmer temperatures. Come to think of it, Mars seems to have more dust storms than it used to when I was younger. I wonder if the sun is up to no good.]]

They found hot spots on Jupiter; they have not found global warming on Jupiter. The hot spots have probably been there (the phenomenon, I mean, not the individual columns) for billions of years. As for big dust storms on Mars, google “Mars Mariner dust 1971.”

The sun can’t be responsible for current global warming on any planet since there has been no noticeable upper trend in sunlight for 50 years or more. We’ve been measuring Total Solar Irradiance from satellites like Nimbus-7 and the Solar Maximum Mission for many decades now, and have good proxies before that.

a 2.4 meter mirror in space can see even relatively dim stars in a fraction of a second exposure time

To be complete, it also helps when you have a really really good CCD, cooled to like -80 degrees C., and you take minutes to read it out. It’s amazing how low much lower the noise can be than in your $500 digital camera.

I don’t actually know how long the readout takes on WFPC2, but it’s about 2 minutes to read out the 16 megapixels of ACS Wide Field Channel, and it’s likely similar. Though of course for ACS right now it’s 2 minutes plus the time between now and Servicing Mission 4.