Astronomy Israel

Tuesday, July 14, 2015

We Finally Know the Size of Pluto

The New Horizons spacecraft is finally close enough to Pluto for its size to be accurately determined: 1,473 miles or 2,370 km in diameter. It is the largest object in the Kuiper Belt, the region of our solar system beyond the planet Neptune. Will this be enough to promote it back to planet from dwarf-planet status? Only time will tell, as it requires a vote of the International Astronomical Union, which demoted the diminutive planet to dwarf-planet status in 2006. Stay tuned and watch for updates from the New Horizons Mission as the satellite flies past Pluto in its closest approach today, July 14, 2005.

Pluto (right) and its largest moon Charon as New Horizons satellite approaches the system.

More information here: http://www.astronomy.com/news/2015/07/how-big-is-pluto-new-horizons-settles-decades-long-debate

Sunday, April 19, 2015

Lyrid Meteor Shower Peaks April 22-23

The Lyrids, the best meteor shower of the first half of 2015 peaks this Wednesday night and in the early hours of Thursday morning, Yom Haatzmaut. Peak rates are around 20 meteors per hour after midnight, although in some years the shower has surprised with peak rates of over 100+ per hour. A meteor shower occurs when the earth passes through the orbit of an old comet that has shed rocky and dusty debris as it orbits the sun. As the earth passes through the debris field bits of cometary particles burn up from friction with the earth's atmosphere, leaving behind a bright train of ionized particles we see as the "shooting star". Most cometary particles are no bigger than a grain of sand, bright meteors perhaps the size of a pea. The meteors appear to emirate from a region of the sky called the radiant. The shower takes its name from the constellation that contains the radiant, in this case the constellation Lyra. You need not be looking at the radiant to view the shower. Just lie down in a comfy spot on the ground or a reclining chair, stay warm with a blanket, and watch the sky. Keep count and see how many meteors you observe each hour, or fraction of an hour. No optical instruments required. In fact, they get in the way since you want as wide a field of view as possible which only your naked eye can provide.

I will be having a star tour the night of April 22. Call or email for a space. The weather is forecast to be clear that night, turning inclement the next day and night.

Friday, March 20, 2015

Solar Eclipse Visible from Israel on Friday, March 20

An eclipse of the sun will be visible across Israel on Friday March 20, coinciding with the first day of Spring, or the Vernal Equinox as astronomers call it. The eclipse will just be partial in Israel, with just 5% of the sun's disk being obscured by the moon. The eclipse will not be visible at all in the US.

The eclipse begins in Israel at 11:17am local time and ends at 12:39pm local time. Maximum eclipse occurs at 11:58am, when just a tiny sliver of the sun, just 5% will be covered by the moon.

Be careful observing the sun. You always need special filters to view the sun with optical aid. They cannot be home made. Observing the sun without proper eye protection with binoculars or a telescope wil result in immediate and permanent damage to your eyes. The same is true if you stare at the sun with your naked eye. Don't do that. You can make a home made pinhole projector to observe the sun, or else use a #14 welders glass, no other value. But the welders glass, if you have one, should only be used with the naked eye, not in front of optics.

If you want to watch totality, go to www.slooh.com, an online telescope where the total eclipse will be shown from the Faroe Islands, weather permitting.

And, of course, the astrologers have to make their appearance, too: http://www.timesofisrael.com/solar-eclipse-friday-has-some-looking-for-signs-from-god/

Good viewing and Happy Spring!


Table of times for the partial solar eclipse of March 20, 2015, visible across Israel. The diagram at the top shows the small sliver of the sun that will be obscured by the moon. See the text above for proper eye protection needed to view the sun. Without it you can permanently damage your vision.

Sunday, March 1, 2015

Did You Catch the Triple Conjunction at the End of February?

Most people around the world in the Northern Hemisphere probably missed the triple conjunction of the moon, Mars and Venus at the end of February. We certainly did in Israel where the winter has been cloudy, windy, rainy, snowy and cold. We even had two snow days in February alone in Mitzpe Ramon! It's been weeks since I've been able to do a star tour.

For those who missed the sight here's a photo of the triple conjunction from Palm Springs, California, looking toward the San Jacinto mountains in the West.

Moon to the right, Venus to the bottom left, Mars between, as seen on Feb. 23 from Palm Springs, California. Photo by Kendigitize.

kendigitizeKen

kendigitize

Triple conjunction over Manhattan by Stan Honda

Friday, February 20, 2015

Venus, Mars and Moon Triple Conjunction

Weather permitting, observers in Israel will have the opporunity to see a beautiful triple conjunction of Venus, Mars and the new crescent moon of Adar on Friday evening, February 20, at dusk. The three celestical bodies will then be within half a degree of each other in the western sky. Half a degree is the diameter of the full moon in the sky. Such close approaches make for very memorable and beautiful displays. Of course, these celestial bodies only appear close together as they align in our line of sight in the sky. The moon is about 230,000 miles away, Mars about 142 million miles away, while Venus is 67 million miles away.

The next night, Saturday February 21, the crescent moon will have moved to the upper left of Venus and Mars, but the two planets will remain impressively close together for the rest of the month. See if you can distinguish them by color. Venus is creamy white, Mars a pale red.