04/05/2017
Here's something fun to do
Before summer ends, here's another chance to see dazzling meteors in the night sky! The annual Eta Aquarid Meteor Shower is already active since April 22 until May 20. The peak will fall on the night of May 6 to the early morning of May 7 PST.
The moon's phase for night of the peak is a waxing gibbous, meaning it is up until 2:30 AM in the morning of May 7. The light from the moon could obstruct fainter meteors but it would set just in time when the radiant rises in the east where it is practically the best time to observe a meteor shower.
In the hours of the shower's peak, one could expect 20-40 obeservable meteors per hour under optimal conditions (good weather, a moonless sky, and away from light pollution). If the conditions are really good, during the hours when the radiant is up in the sky, an expected zenithal hourly rate is around 40-85 meteors per hour. However, the peak will only rise at 2:30 and sunrise around that time is at 5:30 AM.
One distinct feature of a meteor is that it leaves a persistent train, an ionized gas trail that glows for a few seconds after a meteor has passed, and a roughly half of Eta Aqaurid meteors tend to generate these. For a video clip you may watch it here: https://vimeo.com/72910925 at about 00:16 you'll see a meteor pass by and the persistent train glows right after.
For any meteor shower, it is named from its radiant. The Geminids come from Gemini, Perseids from Perseus, and of course, the Eta Aquarids would come from Aquarius, specifically the faint star Eta Aquarii. It is one of of the four stars making up the "Water Jar" asterism. Radiant is the term for the point in the sky where meteors seemingly come from, if you trace back the streaks. You don't have to wait for the radiant though, you can wait and watch for the meteors at any part of the sky, its just where the meteors radiate from.
Do not be confused that the constellation is the actual source of meteors. It is only from our perspective that comets come from a certain constellation. The actual source for the meteors that burn in our sky are actually the debris left by comets or asteroids that tend to come and go in the inner solar system (where Mercury, Venus, Earth, and Mars reside). As the comet weaves in and out of the inner solar system, it leaves a trail of debris that would
eventually be picked up by Earth's gravity whenever our planet would intersect with this trail.
Just before the sun rises, Aquarius and the radiant of the Eta Aquarids will just be 33Âş above the eastern horizon, make sure that you enjoy this small window of opportunity! When a radiant is already in the night sky, would mean that the Earth is "in the zone" of the trail of debris left by a parent comet or asteroid. For Eta Aquarids, it is actually associated with Comet Halley, however these debris have already deviated from the comet's orbital path due to various factors such as gravity, radiation, or interplanetary gas.
For more information, you may visit the articles from Space.com and earthsky.org:
http://www.space.com/36502-eta-aquarid-meteor-shower-guide.html
http://earthsky.org/astronomy-essentials/everything-you-need-to-know-eta-aquarid-meteor-shower -many
Finally, some tips for observing meteor showers:
-You may bring a blanket or a chair for comfortability as you observe the night sky.
-Second, find an area far from the city lights. The moon may not be up for the whole night but city lights generate huge amounts of light pollution,
potentially obscuring faint meteors.
-At the start your observaton, give your eyes some time to adapt to the darkness. This will allow your eyes to become sensitive to light, potentially
increasing the chances of you seeing meteors.
-Lastly, be patient and enjoy! There's plenty of time to observe.
Also please note that we will not be having a public observation for this meteor shower as we have another event on this date. You may watch this at the
convenience of your own place or planned trips as long as the conditions are good. Clear skies everyone!
