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Last couple months we’ve seen some nice conjunctions of Jupiter and the Moon. On January 21st, they will come closest seen from the Earth. They would be seen about half a degree apart at the closest. As a comparison, the full Moon is about half a degree in diameter.
Here is a simulated view of the conjunction.
This conjunction is well placed seen from the western hemisphere, because it happens during the early part of night for this side of the Earth. The closest point being around 7:00 pm Pacific time. If you remember the Moon moves almost 13 degrees in one day,the conjunction may not appear so close from the eastern hemisphere unless you wait until late in night/early morning. In any case, don’t forget to look up at the Moon on 21st January 2013
This conjunction is also a good time to observe the movement of the Moon in the background of stars on the Ecliptic. Jupiter being farther away does not move much in a few hours. But the Moon is much closer, and also there is a the advantage of a bright Jupiter close by – So if you see the Moon at an hours interval a few times in the night, you will easily be able to see how the Moon has traveled towards East in the background of stars.
A bonus this time is the conjunction occurs in a very star-studded region of the sky – surrounded by prominent constellations such as Orion, Taurus, Auriga and Perseus. And by the way, the orange-red star close to the Moon & Jupiter is Aldebaran, also known as Alpha Tauri in sky-terminology, and is the 4th nakshatra Rohini, in the Indian lunar Zodiac.
Here is an article about Stellarium, that appeared on today’s issue of Kannada daily Samyukta Karnataka (9/27/2012). Click on the image for a enlarged view. My article is at the bottom of the page:
If the full page view is hard to read, you may choose to click on the following image, for a better resolution, but without the graphical elements:
(I wrote this article last year for ಅರಿವಿನ ಅಲೆಗಳು by Sanchaya).
By the way, I did not even notice another year has gone by for my blog. Surely, this has been the most inactive year for me on ಅಲ್ಲಿದೆ ನಮ್ಮ ಮನೆ!
By now, every kid on the internet and his or her baby-sitter know that the transit of Venus is a once-in-a-lifetime, twice-in-a-lifetime, or never-in-a-lifetime event. So, I am not going to dwell on that aspect of the transit!
In 2004, when the Venus transited the Sun, I was in the wrong part of the Earth .
Did you ask what do I mean by being “on the wrong part of the Earth”? You see, the transit is an event seen when the Sun is over the horizon. So if the planet were to go in front of the Sun during the night-time, hard luck. Just like a solar eclipse.
Transit 2004 Visibility Map from Wikipedia:
Luckily, I was in the right part of the Earth in 2012, so I did not want to miss the once-in-a-lifetime opportunity!
Transit 2012 Visibility Map from Wikipedia:
Adding to my luck, I was invited by a friend to watch the eclipse from his backyard telescope. Since Venus is so small compared to the Sun, the transit of Venus is better appreciated with an optical aid.
And here is the fantastic view through the 9-inch telescope – captured on my mobile phone.
We also looked through a welder’s glass, and it looked cool too. But could not take a picture through that. By the way, did you notice the sunspots in the picture above ? Compare them to Venus, which is about 12000 miles in diameter – and the enormous size of the Sun spots does strike you!
Yugaadi marks the beginning of the traditional lunar new year celebrated in several states of India such as Karnataka, Andhra Pradesh and Maharashtra. Literally, Yugaadi means Adi – “the beginning of” and yuga – “an era”. As per current understanding, a yuga is a measure of time, associated the term with long periods – as in Krta, Treta, Dwapara & Kali yugas, each spanning thousands of years.
However, if we go back in time for about thirty five centuries, we find Indians had a very different interpretation of the term yuga. Vedanga Jyothisha compiled by Laagadha around ~1400BC very clearly defines a yuga as a period of five years. The very opening verse of Vedanga Jyotisha has the following verse:
pa~ncha saMvatsaramayam yughAdhyakSham prajApatim |
dinartvayana mAsAngaM praNamya shirasA shuchih ||
which approximately translated to the following:
“I bow to thee, Oh Prajapati, one who has the day, season and the half-year as limbs, the over-seer of the five-year long yuga”
Vedanga Jyotisha also tells us when the five-year yuga began based on the alignment of the Sun, Moon and stars (specifically both meeting at the star Shravishta) in the sky. Also, according to the text, five years of a yuga were called samvatsara, parivatsara, idaavatsara, anuvatsara and idvatsara. Incidentally, this beginning of a new yuga took place at winter solstice, and not at (or close to) Vernal equinox as the current yugaadi is.
Things change over time. Now, we call every year a samvatsara, and the five-year long yuga is almost unknown to most people! If you are more interested on this topic, I suggest you to read this paper by B.N.Narahari Achar is a good resource.
Wishing a very happy Yugaadi to all visitors at ಅಲ್ಲಿದೆ ನಮ್ಮ ಮನೆ!
Ever wondered what would you see on a Full Moon day, if you were on the Moon?
Answer: It depends.
It depends on where you are standing on the Moon. If you are on the far side of the Moon that is always turned away from the Earth, then you would be standing in the lunar night. Pretty much you’d see what you would see from Earth in a dark night sky. Except that there won’t be the Moon. And of course, there won’t be Earth too, because you are on the far side.
If you are on the near side of the Moon that always faces the Earth, then it is your daytime! So you would see the Sun, and you’d see a New Earth – which actually can’t be seen, unless of course, it is a solar eclipse occurring at your location on the Moon (which in turn means it is a lunar eclipse for your friends on the Earth).
Since there is no atmosphere, and no dispersion of light, you could see stars and planets, if you can somehow block the sunlight!
Stellarium makes it easy to visualize that. Here is a screenshot from a time few hours from now, when the Moon appears full for earthlings.
You can see the “New Earth” pretty close to the Sun, but not close enough to cause an eclipse. As an aside, there are three planets, and parts of three constellations of the zodiac visible in the screen shot. Click on the image for a better view.