Tag: "nasa"

"Magnified" lunar eclipse? I don't think so

The BBC last week ran a story on Saturday's partial lunar eclipse. I have no objections to the BBC coverage lunar eclipses, but I do have problems with non-science writers covering them.

Just a bit of background, for viewers in Asia and the Americas this lunar eclipse would have appeared while the Moon was near the horizon. The Moon is bigger near the horizon right? Kinda.

The article of the title was "Lunar eclipse 'magnified' in US". A pathetic attempt at trying to make it seem more interesting. The article went on to say:

A partial lunar eclipse taking place on 26 June will appear magnified in the US by an effect known as the "moon illusion". [...] According to Nasa, low-hanging Moons look "unnaturally large when they beam through trees, buildings and other foreground objects". The reason for this is not understood.

NASA huh, well you could have just asked your local amateur astronomer and got an answer. The reason for the effect is NOT unknown.

The Moon, or the Sun for that matter (please don't look directly at the Sun), do look larger when they're near the horizon compared to high in the sky. However you can take a simple measurement to show they're the same size regardless of where they are in the sky, about half a degree across.

The effect is an optical illusion created by our brains. Our brains use other objects to estimate the size of things. Trees and houses, things you'd see on the horizon are pretty big. The Moon looks like it's close to them and about the same size or bigger, so hmmm the Moon must be big too. When the Moon is off by itself high up in the sky we have nothing else to compare it to.

Effect not unknown.

Phoenix lands successfully

One last thing I wanted to leave you with before I head off to Newport to see Catherine. Phoenix landed successfully last night! Here's the first image of the horizon we've got back.

One thing I do have a comment to make quickly about, have you seen what the NASA personnel are wearing? Those silly blue t-shirts that make them look like McWorkers. Honestly NASA, let your people wear a shirt and tie instead of a dumb uniform somebody like Game would come up with, it looks much more professional and it isn't going to get any young people going into engineering or science.

Phoenix Mars Mission

Two days five hours to go until Phoenix lands on Mars, the mission is what NASA have dubbed a quick scout mission, where it'll briefly look into history of water on Mars and any habitability potential in the ice-rich soils near the Martian poles.

Phoenix itself will land on Sunday at 23:53:52 (+/- 46 seconds) UT (Monday 00:53:52 BST), as you can see from the drawing above there will be no penny-pinching inflatable beach ball landing for this mission. I'm hearing it'll be broadcast on NASA TV, which should be interesting as I've recently got NASA TV working on my Xbox 360 Media Center Extender again. It'll be doing some of the work that the lost Mars Polar Lander was supposed to be doing.

Emily Lakdawalla will have more details as they roll in on the Planetary Society blog.