Four Moons

Four moons of Saturn at once!  Click for larger. Credit: NASA/JPL-Caltech/Space Science Institute

Four moons of Saturn at once! Click for larger. Credit: NASA/JPL-Caltech/Space Science Institute

We get to see four of Saturn;s moons in this Cassini image. NASA describes them below. They do not comment on one of more spectacular shots of the rings Cassini has taken; they show up better in the larger versions at the NASA website.

Two pairs of moons make a rare joint appearance. The F ring’s shepherd moons, Prometheus and Pandora, appear just inside and outside of the F ring (the thin faint ring furthest from Saturn). Meanwhile, farther from Saturn the co-orbital moons Janus (near the bottom) and Epimetheus (about a third of the way down from the top) also are captured.

Prometheus (53 miles, or 86 kilometers across) and Pandora (50 miles, or 81 kilometers across) sculpt the F ring through their gravitational influences. Janus (111 miles, or 179 kilometers across) and Epimetheus (70 miles, or 113 kilometers across) are famous for their orbital dance, swapping places about every four years. They are also responsible for gravitationally shaping the outer edge of the A ring into seven scallops.
This view looks toward the sunlit side of the rings from about 47 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 11, 2013.

The view was acquired at a distance of approximately 810,000 miles (1.3 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 47 degrees. Image scale is 47 miles (76 kilometers) per pixel.

The “Other Earthrise”

The less famous Earthrise image. Credit: LOIRP

The less famous Earthrise image. Credit: LOIRP

Very nice! This is an Earthrise image taken by Lunar Orbiter 1 in 1966. The Lunar Orbiter Image Recovery Project (LOIRP) just released the newly enhanced image they call: the “Other Earthrise.

The image is actually one of two images taken. The first of the pair was released by NASA is of course famous and one you’ve probably seen before.

There is a great story and more images at Moon Views – The Lunar Orbiter Image Recovery Project (LOIRP).

Ready to Go

A gallery of images (hopefully) is lead off with a long exposure photo by Bill Ingalis (Credit: NASA / Bill Ingalis) showing the gantry arms moving into position to secure the Soyuz TMA-12M spacecraft at the Baikonur Cosmodrome in Kazakhstan in preparation for a 26 March 2014 launch. The gallery shows the Soyuz roll out.

The spacecraft will transport Expedition 39 Soyuz Commander Alexander Skvortsov (Roscosmos), Flight Engineer Steven Swanson (NASA), and Flight Engineer Oleg Artemyev (Roscosmos) to the International Space Station where they will participate in a six-month mission.

If all goes well I will have viewing links up before the launch. Fingers crossed for the ISP to hold it together though.

DEM L241

A supernova and a surviving companion star. Click for larger. Image credit: X-ray: NASA/CXC/SAO/F. Seward et al; Optical: NOAO/CTIO/MCELS, DSS

We are looking at a binary star system or rather what is left of a binary star system after one of the stars goes supernova. The surviving star is hidden the debris field of the supernova but it survived the explosion. I have to wonder what that star is going through, I’d be surprised if it wasn’t undergoing changes because of the explosion, I can picture siesmic waves ringing through it. We will probably never know for sure.

The image above is a composite of contributions from the Chandra X-ray Observatory and other telescopes including those in Chili and the Digitized Sky Survey.

There are desktop sizes to the image and they are wonderful! You can get them and read the details on DEM L241 here.

It’s Spring!

Today is the March Equinox. Finally! The equinox occurred at 16:57 UTC.

For me, the winter has been long and cold, March alone has been 12 oC below normal. In fact it is still cold. Maple syrup producers have hardly made a drop so far.

A cartoon depicting the angle of sunlight lighting the Earth’s surface. Image by Przemyslaw “Blueshade” Idzkiewicz.

So the March equinox heralds longer days for the northern hemisphere and shorter days for the south. On the day of the equinox the tilt of the Earth is more or less balanced as you can see in the cartoon above.

Equinox

late 14c., from Old French equinoce (12c.) or directly from Medieval Latin equinoxium “equality of night (and day),” from Latin aequinoctium “the equinoxes,” from aequus “equal” (see equal (adj.)) + nox (genitive noctis) “night” (see night). The Old English translation was efnniht. Related: Equinoctial.

- Online Etymology Dictionary

Most of you have no doubt noticed the date of equal and night does not necessarily occur on the equinox (today for example). The day that comes the closest to 12 hours day and night depends on your latitude. For my latitude (~45 N) that day was this past Monday.  Here is a good explanation of why.

The image below attempts to show this day length / latitude relationship, and while it isn’t down to the minute or anything, it depicts how things progress during the year. That and I liked it.

Amount of daylight through the year at different latitudes. Image: Creative Commons

 I did not see the onslaught of feats of egg balancing on the equinox this year! :mrgreen:

163 Erigone

If you happen to be up at 0605 UTC (20 March 2014) and many will, you can watch the 72 km (45 mile) wide asteroid 163 Erigone eclipse the star Regulus.

The visibility will occur for people in a narrow swath in the north eastern portion of the US and into Ontario Canada. See below:

Ground track of 163 Erigone via the Creative Commons

Ground track of 163 Erigone via the Creative Commons

Tthe vast majority of us will not be able to stand outside and see it, HOWEVER we will be able to WATCH IT LIVE AT Slooh.

Explore the Lunar North Pole

The north pole of our moon. Image Credit: NASA/GSFC/Arizona State University

The north pole of our moon. Image Credit: NASA/GSFC/Arizona State University

 

You have to check this out!

Scientists at NASA used the Lunar Reconnaissance Orbiter has released the first high resolution interactive mosaic of the lunar north pole. What a bit of work, some 10,581 images went into the making of the image. You can pan and zoom down to an image resolution of two meters (six-and-a-half feet) per pixel.

Here’s the link.

Enjoy!