Wednesday, February 3, 2016

Carnival of Space #443

It is a time for another carnival of space. Did you manage to see all planets together in the dawn sky? After several rainy and cloudy mornings I got up at 6 am and was able to see all of them. Mercury was definitely the hardest as the sky were quite blue. It was about 30 minutes before sunrise and I will try even earlier later this month. Taking a photo of all planets is harder as they span over 100 degrees and a very wide lens is required (or taking several photos and stitching them in software).
Here is an illustration of the planets and some photos of the (not all together) planets.
All planets together illustration by Stellarium software
All planets together illustration by Stellarium software

More planets at the end. And now for this week articles:
From Aartscope blog:
  • Astroswanny is tracking asteroid 2016 BE, an interesting 79m asteroid on the risk table for 2076-2111 discusses what a Virtual Impactor is in order to demystify some of the asteroid terminology.
From Ryan Marciniak:
From Universe Today:
From Chandra's blog:
From About Education:
From the Venus Transit archives:
  • The space shuttle, an article in respect to the crews of Columbia and Challenger space-shuttles.
And as promised, more planets. Notice the red hue of Mars in the first photo 
Moon and Mars (31/1/2016
Moon and Mars (31/1/2016)
Venus and Mercury - 31/1/2016
Venus and Mercury - 31/1/2016

Thursday, January 7, 2016

The moon, Venus and Saturn conjunction

Today (Jan 7th 2016) there was a very nice planetary trio. The moon, Venus and Saturn formed an almost equilateral triangle in the early dawn sky. The distance between any pair of celestial bodies was about 2.5 degrees.
All orbs were in the constellation Ophiuchus (Oph). There are only 12 signs in the zodiac but in the modern division of the sky into constellations, it turns out that the sun also travels through Ophiuchus for some days in the year (The moon can be in even more constellations!)

Here are some photos

The trio. Venus is very bright and Saturn is the dimmer star below.
The moon Venus and Saturn
The moon Venus and Saturn
A wide field photo with part of Scorpio constellation in the right side of the photo. You will probably need to enlarge the photo to see it properly, and even see some of the red hue of Antares. Scorpio is a summer constellation and in the winter it rise just shortly before sunrise. 
The moon Venus and Saturn
The moon Venus and Saturn
Using longer exposure we can see the Earthshine and many dim stars. You will need to enlarge this as well. Notice HIP81695 which is on the right limb of the moon and two small stars (HIP81632 and HIP81754) above Saturn.
The moon Venus and Saturn
The moon Venus and Saturn
The last photo is on brighter sky just before sunrise.
The moon Venus and Saturn
The moon Venus and Saturn

Monday, December 7, 2015

Carnival of space #435

Hello and and welcome to Carnival-of-Space #435. If you are from North America maybe you saw (or still able to see ) the Venus daytime occultation today (7-Dec-2015). I am from Israel and the occultation is long after the moon sets. Here is a photo from this morning they are so close and getting closer by the hour! Venus is at the bottom left. the photo was taken with a smartphone camera (LG G4). Indeed anyone can take such a photo so go and try (Just make sure that the sun is blocked from your view)!
The moon and Venus (bottom left) 7-Dec-2015
The moon and Venus (bottom left) 7-Dec-2015

Here is also my video from 2007. Also, get ready for the Gemenid meteor shower next week. Plan ahead for either Saturday, Sunday or Monday night according to your location and enjoy.

And holidays are taking place. The Jewish world is celebrating Hanukkah and others are getting ready for Christmas and new year. Here is the traditional Menorah with Venus and Jupiter as candles. Happy holidays to you all, regardless of your faith and beliefs, may your life be filled with light and happiness!!!

Whats in CoS this week?

From Planetaria:
  • Drones on Mars? small ‘helicopter-like’ scout could be added to Mars 2020 rover mission.
From EverydaySpacer
  • The Year in Space 2016 looks like a great Calendar.  Steve Cariddi has done it again!  In cooperation with The Planetary Society, read about the next great Wall Calendar that's more like a changing poster.  More beautiful pictures, bio and historical facts will entertain you for another 12 months!
From NextBigFuture:
  • "NASA’s Solar Probe Plus mission — which will fly closer to the Sun than any spacecraft has before — reached a major milestone last month when it successfully completed its Critical Design Review (CDR).
From UniverseToday:
And an interesting fresh photo of Earth and moon from Japanese mission Hayabusa 2 from last week taken 3 million KM from Earth toward an Earth flyby in the way to its destination. I like "Earth from space photos" and collected many of them to this article in the link mentioned. That's all for this week. 
Earth and moon. Hayabusa 2 25-11-2015.
Earth and moon. Hayabusa 2 25-11-2015. Credit: Jaxa

Sunday, November 22, 2015

Stars of Joseph

The dreams of Joseph is a  known episode from the bible (Genesis 37 9): "Then he dreamed still another dream and told it to his brothers, and said, “Look, I have dreamed another dream. And this time, the sun, the moon, and the eleven stars bowed down to me.”" (The quote is from NKJV but you can see many other translations here")

An interesting question, from an astronomer's point of view is just which eleven stars Joseph saw in his dream (If you are a soccer/football fan you can probably think of your favorite team). I didn't find much discussion on this or an answer so I will suggest my own interpretation to the text.

My attempt is to give the dream a realistic meanning. The first thing to notice is that Joseph could not see the sun and moon and the stars together. While it is possible to see the sun and the moon together it is impossible to see stars during daylight (surly not 11 stars). So the dream is not a single moment but span over some time. Another  thought is that Joseph saw the planets but at that time in the ancient world only 5 planets (beside the sun and moon) were known which leaves us with six unidentified stars. Another option is to choose the brightest stars in the sky (seen from latitude 32 North), However what is the meaning of a bowing star, and the brightest stars are not seen at the same time or even in the same season, and it seems just to be random stars which is quire meaningless.

Lets consider the action of "bowing". Bowing is a gesture in which one falls down and then rise up again, and this reminds me of a setting or rising star. A setting star performs the bowing and the rising star gets up from that same bowing.

Pondering all these points, here is my  suggestion. Joseph saw 11 stars setting or rising, together with the sun and the moon. The number 12 is a famous one. There are 12 months in the calendar and there are the twelve tribes (Sons of Jacob) and there are the 12 constellations which represent the different months. Let us assume that each star is actually the brightest star in one of the Zodiac's constellation (or the complete constellation) so Joseph saw all 11 constellations. This is possible every night if you observe from sunset to sunrise.

Joseph's dream spanned over an entire night. Immediately after sunset Joseph saw the little moon crescent sets as well and than saw some constellations set and some rise. The old Jewish scholars also paired between each tribe and a month/constellation so which constellation Joseph didn't see? His own constellation of course which is either Aquarius or Pisces (according to different Jewish traditions).

Notice that the moon sets immediately after the Sun (and before the stars) so the time was a new Lunar month which is the beginning of a new month in the Hebrew calendar. Taking that information a leap forward and calculating the age of Joseph (17 at that time) from the creation we find that the dream happened in the beginning of the 11 or 12 Lunar month of year 2216 from Adam which in converting to our Gregorian calendar will be circa January or February 1544 BC (the conversion formulas are not accurate to give a specific day). I
I find it interestng that such intepretation can lead to an actual date.

Also I find the intiutive solution to the dream to be wrong. Jacob, Joseph's father interpret the 11 stars as Jospeh's brother and sister while he is the sun and Josephe's mother (poor Rachel which has passed away alread) is the moon. I suggest to think about the 11 stars as eleven years that passed on Joseph in Egypt with 2 more years until he was released from prison. The sun was an important god for Egypt and the fact that all celestial objects bows to him means that he will have some control over the nature as he had some lter during the drought years.

Joseph dream
Joseph's dream - Unknown artist from Henry Davenport Northrop book 1894

For some reason this well known picture of Vincent van Gogh "Starry Night" reminds me of Joseph's dream.
Starry night - Van Goch
Starry night - Van Goch 1889 -  (MOMA New-York)
A huge moon and 11 stars and maybe the tree seems a bit like a bonfire which resemble the sun...

The painting gave inspiration to Don McLean with his version of "Starry Night" in the song "Vincent"