Astronomy Israel

Sunday, April 22, 2012

Romance (and Saturn) is in the Air

Coming on the heels of our being named a Top 10 Romantic Tour for Valentine's Day in Israel by israel21c.org, we were named a Top 10 Wedding Guest Tour by Hatunotblog.com. Lee Balot and Yoash Limon, desert tour guides and proprietors of the Greenbackpackers Hostel, gave us the opportunity to strut our stuff last Thursday by throwing a wedding star party for their guests in Mitzpe Ramon. About 18 people joined them for a night under the stars from our observing location above and behind Mitzpe Ramon. Aside from the bride and groom, Saturn was the star, so to speak of the evening, who stole everyone's heart. I've gotten comments on Saturn for this apparition like, "No Way!", or "You painted that on the lens!", and "This is the highlight of our tour!" Yes, Saturn is that good. Sometimes it all people will let me show, so I try to show it last. The thing about Saturn is that it looks exactly like you expect t to, even in a small telescope. It's too far away for the largest telescopes to show much more detail than a small one, and the main features are large enough to show well in small telescopes. It's the amateur's "Goldilocks planet".

A few people try to capture a photo of the planet with their cameras or iPhone, usually to no avail. It's just too hard to hold the camera steady over the eyepiece to get a shot. But one resourceful guest, Estee Nemeth, who is in the film industry, used her iPhone's video and edited the stream down to the one good frame that showed Saturn well.

Saturn, by Estee Nemeth

It's a bit overexposed and blurry, but there's no doubt about what it is. You can even see the outer charcoal colored A ring and the inner, bright B ring. The pencil thin dark line that separates them is the Cassini Division, where ring material is absent. The photo below shows many of the details that can be seen on a good night with our telescopes. But you must have excellent, steady "seeing", and also alot of patience and time at the eyepiece. As I tell people, "It's called observing, not looking."

Saturn, by Bob English

Last Friday Lee and Yoash got married. We wish them Mazel Tov, and send us some guests!!

Yoash Limon and Lee Balot

Sunday, April 8, 2012

Follow the Zodiacal Light

zodiacal light reflecting off dust in solar system (Photo credit: Wikipedia)
Many people may be away from home for the Pesach holidays, perhaps even at dark sky locations. If so, look to the west shortly after nightfall to see the elusive Zodiacal Light. It is a bright pyramid shaped cone, wide at the bottom near the horizon, tapering to a peak at the top. It will be marked by a line connecting the bright planets Jupiter, closer to the horizon, and Venus to the above left. The line conecting these two planets passes through the ecliptic, the plane of the earth's orbit around the sun. The other planets and our moon lie within a 5 degree radius of the ecliptic, so they are never far from it. The ecliptic is called the Zodiac by astrologers, and for the same reason the sun, moon, and planets are always found within the constellations of the Zodiac.

Tonight Jupiter is in Aries and Venus is in Taurus, Venus having just put on a magnificent show passing the star cluster, the Pleiades, last week. The Zodiacal Light is a dim, elusive cone of light that is the reflection of sunlight from billions of grains and dust that lie in the plane of our solar system. The earth is constantly bombarded by these throughout the day and night, but most are too small to show as meteors. Consider them to be motes of cosmic, solar system dust that light up as they reflect the light of the sun at evening. Now is the best time of year to observe the Zodiacal Light, since the plane of the ecliptic makes an almost 90 degree intersection with the horizon, lifting the Zodiacal Light high in the sky and making it readily visible from dark, clear skies. The path of the ecliptic is marked by Jupiter and Venus, so the zodiacal light should appear along the line connecting them. Go outside and have a look and let us know if you can spot the Zodiacal Light. When you do, remember you are seeing a light show put on by the dust that fills the plane of the planets' orbits around the sun.

The Zodiacal Light, as it appears along the line connecting Jupiter and Venus, shortly after dark tonight, April 8, 2012

Tuesday, March 27, 2012

Venus Reaches Greatest Eastern Elongation Tonight

Venus, Jupiter and the moon continue to put on their grand show tonight (March 27th), with Venus reaching greatest eastern elongation for this apparition at 46 degrees from the sun, almost the most distant it can be (47 degrees). Venus never ranges far from the sun, since its orbit is interior to the earth's, making it what astronomers call an "inferior planet", no value judgement intended!

This diagram shows the elongations (or angle) of an inferior planet relative to the Earth and Sun. (Photo credit: Wikipedia)

You can continue watching this shinning apparition tonight and tomorrow night, as the waxing crescent moon joins Venus and Jupiter for a last hurrah in the west, shortly after sunset and continuing on for about 3-4 hours until they set for northern hemisphere observers.

Enjoy it while you can, since the next time the moon comes this way Jupiter will be almost lost in the sunset glow as it goes behind the sun for its conjunction in May.

From top right down: Pleiades, Venus, Moon (overexposed waxing crescent), Jupiter, and a myriad of stars abounding above the dome of the Weiss Observatory in Mitzpe Ramon.

Sunday, March 25, 2012

Venus and Jupiter - Now with the New Moon on March 25th

Venus and Jupiter continue to dazzle with their evening display shortly after sunset, this time adding the new moon of Nissan to their retinue. Look to the west tonight, March 25th, and you will see dazzling Venus just above and to the right of dimmer Jupiter, with the waxing new moon crescent very close and to the right of Jupiter. This is the new moon of Nissan, the month of miracles and our redemption from Egyptian bondage, approximately 3300 years ago. It was this new moon of Nissan that Hashem showed Moshe in Egypt to teach him the laws of Rosh Chodesh and the calculation of the calendar, on which the Jewish holidays depend.

Since our calendars are now all calculated and based on what we know about astronomy and the orbits of the moon and earth, it took me a long time to realize that the Jewish new month was originally just an observed phenomenon. Two witnesses were required to report their sighting of the new moon to the Sanhedrin, who already knew when the new moon was supposed to be and what it should look like in the sky. But witnesses were still required. If they didn't show up by the day after when the Sanhedrin had calculated the new moon, the previous day was declared Rosh Chodesh. This, by the way, is why Rosh Hashannah has always been a two day holiday, even during the time of the Beit Hamigdash and the Sanhedrin, since a tardy witness would cause one to miss Rosh Hashannah. By making the holiday two days, that would never happen.

In this way, even the recognition of what is an astronomical event, based on the laws of gravity and the laws of nature, becomes a partnership between Hashem and the Jewish people.

Above Venus we see the asterism, the Pleiades, the Seven Sisters of Greek mythology. This ia a star cluster some 100 million years old. All stars are born in clusters like this. Come on a star tour and we will see many different ones in different stages of star birth. Through binoculars it is a lovely sight, showing many more than the 5-6 members the naked eye sees. In a telescope or giant binoculars hundreds of stars can be seen.

While you're out with binoculars, take a closer look at Jupiter. It has four bright moons, at least one or two of which should be visible in your binoculars. These are called the Galilean Moons of Jupiter, discovered by the great Italian scientist and Astronomer, Galileo in January 1610.

Tomorrow night, March 26th, the trio will continue to put on their display, but with the moon close to Venus instead of Jupiter.

Good viewing and have a wonderful Pesach. May it be a month full of wonders and miracles for you and all Israel!

My photo of the above event in haze and clouds from Mitzpe Ramon March 25, 2012 at 7:00PM

Tuesday, March 13, 2012

Venus and Jupiter Come Together Tonight

Have you been watching the beautiful light display that Jupiter and Venus have been putting on in the western sky just after sunset? For the past month they have been the two luminaries that have graced the eveing sky with their magnificent beacons, Venus the brighter and lower of the two. Tonight, March 13, they reach their closest approach to one another. After this they continue their separate ways as Jupiter sinks into the west as it approaches conjunction with the sun, while Venus continues its easterly trajectory toward greatest eastern elongation on April 22. Watch them tonight and throughout the next month as they continue to put on their show.

The Southern Lights

The Aurora Australis, or Southern Lights, is the southern hemisphere's counterpart to the Aurora Borealis, or Northern Lights. Problem is, fewer people live down there so we don't get to see photos very often. Going where others fear to tread, the International Space Station (ISS) took this fabulous photo of the Aurora Australis from earth orbit as it passed between Antarctica and Australia. These auroras are the results of solar flares from the sun which shoot charged particles into space that interact with the earth's magnetic field, causing neon-like glows in the atmosphere.