Emily Lakdawalla • Dec 30, 2008
I spotted Mercury last night!
Last night -- actually I guess it was the night before -- I was wheeling out of the grocery store with my daughter and my mother, and I looked up and pointed out the brilliant beacon of Venus to both of them. The skies in Los Angeles are too bright to contain many stars, but the city lights can't ever drown out Venus as long as it's high enough in the sky. My daughter pointed out the skinny crescent of the Moon, and I showed Mom how you could keep going down in an arc from Venus and the Moon to find Jupiter, fairly low in the sky and nothing like Venus, but still bright and steady. I've been looking out in the evenings for Venus and Jupiter ever since their gorgeous conjunction with the Moon last month.
But then something else caught my eye, another steady light, shining a little lower and off to one side of Jupiter. I stopped my cart and stared at it for a minute to see if it blinked or moved -- odds are good in Los Angeles that a bright light in the sky is an aircraft, but no, it was steady and still. It had to be a planet. But which one? It had a sort of orangish hue, but it was close to the horizon so that could just be the color of the atmosphere. I knew that we were only just coming out of Mars' solar conjunction, so it couldn't be Mars -- this one was too far from the Sun. Could it be Saturn? It didn't seem likely, because I knew that Saturn's solar conjunction is coming up in the summer, close to Saturn's equinox, so Saturn should be pretty much on the opposite side of the sky from the Sun right now. There's only one naked-eye planet left: Mercury. I spotted Mercury!
Those of you who regularly look up at your skies are probably saying, "big deal." But, strange as it may seem, I've never been very much in tune with what's happening over my head -- I'm one of those oft-hated morning people who itches to get out of bed when the sun rises, and fades quickly when it sets. I'm usually too busy and distracted even to remember what phase the Moon is in, and I've always lived in cities so I hardly know what a star-filled sky looks like and can only recognize a few constellations. So, I'm sad to tell you, that was, I think, only the second or third time in my life I have looked up in the sky and seen Mercury and known that I was looking at the innermost planet, bound closely to the Sun, until recently one of the biggest unexplored places in our solar system.
I couldn't stare for long; I had to get the groceries into the car and go home and cook dinner and do all the things that keep me too busy for me to remember what's happening over my head. But for a few minutes, anyway, I looked up from the brightly lit grocery store parking lot and contemplated the span of our solar system, three planets and the Moon spread out across the sky.
Mercury never hangs out in any one place for long. According to Sky & Telescope's handy "Sky at a Glance" web page, Jupiter and Mercury will be closest together tomorrow night, so, if you think of it, wander outside and look to the west just after sunset to take a look; at the same time, Venus and the crescent Moon will make a beautiful pair higher in the sky.