Showing posts with label sky. Show all posts
Showing posts with label sky. Show all posts

Saturday, January 12, 2019

Heads Up: Total Eclipse of the Moon Sunday Evening January 20



On Sunday evening, January 20, there will be a nice total lunar eclipse (where the Earth’s shadow darkens the full moon) visible in all of North America. Since this is the day before Martin Luther King Day in the U.S., many students will not have school the next day and can stay up to enjoy the celestial spectacle with their families.
Total eclipses of the Moon are perfectly safe to look at, don’t require special viewing equipment, and are visible all over one hemisphere of planet Earth. Your eyes are just fine to see the show. This is quite a contrast with the total eclipses of the Sun, where viewing can sometimes hurt your eyes, special equipment is a big help, and the best show is only visible in a narrow path. As Bernie would say, the lunar eclipse is for the 99%, not just the special 1%!
A more detailed information sheet I put together (with questions and answers, plus the timing in each time zone of the continental U.S.) can be found at:
http://bit.ly/mooneclipse2019 
Here is wishing you a cloudless evening, and a few hours thinking about the heavens and not the craziness in Washington.
[Our beautiful photo is by Conrad Jung of the Chabot Space and Science Center, 2007]

Saturday, September 7, 2013

Crescent Moon and Venus Get Close Sunday Night Sept. 8


A minor, but cute, pairing is visible in the sky tomorrow. It happens soon after sunset and you can only see it if you have an unobstructed view of the west-southwest horizon. (For many of us that means we will have to get high -- only in the geographical sense, mind you!! Typically, our view is blocked by buildings, trees, hills, etc. and we can't see the western horizon.) But if you get to a place where you can see low in the west Sunday evening, you will see a very thin crescent Moon and the bright planet Venus just to the right of it.

You can start looking about a half hour after the Sun sets on Sunday and you'll see it best about 45 minutes after sunset. But don't wait too long to catch it; soon both objects will set in the West, and disappear from your view.

When Venus is visible just after sunset, people call it the evening star. But it's not a star at all, but a planet -- our neighbor planet just sunward of the Earth. It reflects quite a bit of sunlight both because it's close to the Sun and because it's covered with clouds that are quite reflective. (In fact Venus is so cloudy, there hasn't been a clear day there in 3 billion years. I like to cheer up my friends in Seattle by telling them that.)

As you can see in the nice diagram, which I borrowed from the good people at Sky & Telescope magazine, if you look further up and to the left, you will also see the planet Saturn in the same part of the sky. The distance in the sky between the Moon and Saturn should be about the width of your clenched fist, if you hold out your hand at arm's length. If you have binoculars or a telescope, you can enhance your view, but if you don't have an instrument, it's still fun to look. If you have kids, bring them outside and show them the sight too. It couldn't hurt to impress them with your knowledge of the universe while they are young.


For more information, you can see the full story at the Sky & Telescope web site: http://www.skyandtelescope.com/observing/highlights/Crescent-Moon-and-Venus-Put-on-a-Show-222505621.html

Wednesday, August 7, 2013

Good Meteor Shower Starts This Weekend



Whenever small chunks of cosmic dust or dirt hit the Earth's atmosphere at high speed and heat up, they make a flash of light that's visible from the ground. We call these meteors or "shooting stars." When the Earth encounters an organized swarm of cosmic material, we call it a meteor shower.

The Perseids (one of our most reliable meteor showers) is best this year the night and morning of Sunday Aug. 11 to Monday Aug. 12, and the night and morning of Monday Aug. 12 to Tuesday Aug. 13th.

Watching for meteors is easiest for most people’s schedules in the evenings (before midnight). However, the meteor display is generally better after midnight (making night owls and early risers happy.)

The Perseids are better after midnight for two reasons this year:

a. The Earth turns after midnight to face the shower (so that the meteors are coming more directly at us)
b. The crescent Moon will set by then, so its light will not bother meteor shower fans. (On Aug. 11, the Moon sets at 10:32 pm, while on Aug. 12th the Moon sets at 11:10 pm.)

Whenever during those two nights you decide you want to watch, here are Fraknoi’s Friendly Meteor Shower Tips for best viewing:

1. It’s more important to decide WHERE to watch them, than WHEN to watch them. The crucial issue is that meteors are faint, so you need a location where the sky is DARK. That means getting away from city and car lights as much as possible. The darker your site, the more you will see.

2. Of course, if it’s foggy or cloudy, you won’t see a thing. So make sure you get to a place where the sky is not only dark but CLEAR.

3. Don’t use a telescope or binoculars. (Meteor showers are one of the most democratic of sky shows; those of us in the 99% can enjoy them as much as those in the 1%!).) Your eyes are the best tool, because the flash can be anywhere in the sky. So restricting your view to a small part of the sky makes it more likely you will miss many of the meteor flashes.

4. Dress warm for night-time temperatures and be patient. Meteor showers are far more subtle than fireworks. You will need to relax and wait for time to pass. First, it takes a while for your eyes to get adapted to the dark (I recommend at least 15 minutes) and, second, a minute or several minutes might pass without a single flash. Eventually, though, you should see significantly more shooting stars than on a regular night.

5. So (perhaps most important) try to take someone with you with whom you like to spend time in the dark.

The Perseid meteors are cosmic “garbage” (dust and dirt clumps) left over from a regularly returning comet, called Swift-Tuttle (after the two astronomers who first discovered it). When comets get near the Sun, their ice evaporates, leaving behind some of the dirt that was frozen inside them. Since comets are "left-overs" from the early days of our solar system, you can tell yourself that each flash you see is the “last gasp” of cosmic material that formed about 5 billion years ago.

(Our photo, by ESO Photo Ambassador Stéphane Guisard, shows a bright Perseid meteor in 2010 over the grouping called the Very Large Telescope at the European Southern Observatory in Chile.)


Sunday, March 10, 2013

Comet PanSTARRS: Beware of the Internet Hype, but Check out the Sight


This coming week is perhaps the best time to look for a new comet in our evening skies, as long as your expectations are not set too high by some of the media attention it has received.   The comet – a chunk of ice and dirt from the distant backwaters of the solar system – is falling around the Sun with closest approach to our star on Sunday, March 10th.  



For the next week, it will be visible very low on the horizon if you look toward the west.  Tuesday and Wednesday it will be near the crescent Moon and may be easier to spot as a result.  But here are the problems beginners will need to keep in mind:

1. It’s so low in the sky you will need to look for it from a location where you have a clear view all the way down to the western horizon -- and no hills, buildings, or trees in the way.  Out by the ocean is really great.

2. Things on the western horizon are SETTING – going quickly below the edge of the sky.  That means there is a very short window to see the comet.  Try too early, and the sky is too bright with sunlight.  Try too late, and the comet is below the horizon.  About 30 - 45 minutes after sunset is what experts are recommending.

3. If there are clouds or fog in the western direction, or you’ve got bright street or car lights in your view, the comet may be too hard to see.  In March, weather is an issue in many locations.

4. And the comet is so far from Earth, it is not spectacularly bright. In general, binoculars may be needed to pick the head of the comet and the faint upward-pointing tail out of the glow of the sunset.


By the way, if you are wondering about the strange name for a comet, it’s taken from the automated survey telescope in Hawaii that discovered it in 2011: the Panoramic Survey Telescope and Rapid Response System. 

Sunday, January 20, 2013

Look Up in the Sky Monday Night


As the Sun sets on Monday evening, Jan. 21, and you face South and look up, you should see a pretty sight. The planet Jupiter will be very close to the Moon, almost cheek to cheek with it. Their "closest approach" in the sky will be around 7 pm Pacific time.

The two just happen to look close on the sky -- in reality, Jupiter is 1,700 times further away. Jupiter is the largest planet in our solar system -- eleven Earths could fit side by side into its diameter.

As an extra treat, you get to see the bright star Aldebaran just below the Moon-Jupiter pair. Aldebaran, the reddish eye of the bull figure that gives its name to the constellation of Taurus, is a cool giant star, about 44 times as wide as the Sun. It is about 67 light years away, meaning the light we see tonight took 67 years to get to Earth. If you could see Aldebaran up close, it would shine over 400 times as bright as the Sun. But with all that distance between it and us, it's just a reddish point in our sky.

As you can see in the diagram, the Moon and Jupiter are already close tonight and will still be close on Tuesday night. But Monday is the best time to look up. Take the kids outside in the evening or make a date to be outside with someone with whom you like to spend time in the dark.

(Thanks to Sky & Telescope magazine for the diagram I am showing.)