The story of Rosetta and Philae - Cartoon series from ESA

Credit : ESA

ESA's mission to the comet 67p (Churyumov-Gerasimenko) is pictured as a kid friendly cartoon animation series. It tells a brief real life story of the Rosetta mission. No doubt, its not only for kids, but for us adults too. So much informative and with a heart warming storyline to make it understandable for all the ages. ESA released the cartoon in 5 languages (English, Italian, French, Spanish and German). Here I'll provide the playlist in English. For other videos you can check out ESA's Youtube channel.

Rosetta Philae cartoon

• Wake up Rosetta
• Are we there yet?
• Comet landing
• Living with a comet

Here is the playlist - ESA Rosetta and Philae Cartoon

The journey is still continuing and we have to wait for the next event to happen in the mission, to watch the next episode.

Know the Constellation - Canis Major

Last time we checked out the Orion constellation. Now its time for Canis Major. Canis Major is located in the southern celestial hemisphere. The name literally means, "The big dog". Canis major, beside the much smaller constellation, Little Dog, is commonly portrayed as accompanying the legendary hunter, Orion. It contains largely of young blue stars. The most important stars within the constellation are, Sirius, Adhara, Wezen and VY canis Majoris.

Sirius, the brightest star in the night sky, is a Spectroscopic Binary star. It is twice as bright as Canopus, the next brightest star. It appears bright because of both Sirius's intrinsic luminosity and proximity to Earth. Sirius is twenty five times additional luminous than the Sun, however features a considerably lower brightness than other bright stars like Canopus or Rigel. Sirius system is one of Earth's near neighbours.It is approx. 9 light years from Earth.The sky location for Sirius is : RA 06h 45m 08s, Dec -17°16' 42".

Know the basics of sky gazing, Sky Gazing for Beginners - Part I

Adhara is a star in Double system. It is the second brightest star in the constellation. The name Adhara came from Arabic, meaning "Virgins". It is one of the brightest known extreme ultraviolet sources in the sky. About 4,700,000 years ago, Adhara was only 34 light years from the Sun, and was the brightest star. It is approx. 405 light years from Earth. The sky location for Adhara is : RA 06h 58m 38s, Dec -29°01' 41".

Wezen is a yellow-white supergiant variable star. It is approx. 1607 light years from Earth. The sky location for Wezen is : RA 07h 08m 23s, Dec -27°36' 25".

VY Canis Majoris is a single star categorised as a semi regular variable with an estimated period of 2,000 days. If placed at the position of Sun, VY Canis Majoris's surface would extend on the far side the orbit of Jupiter, though there's still sizeable variation in estimates of the radius. It is approx. 4892 light years from Earth. The sky location for VY Canis Majoris is : RA 07h 22m 58s, Dec -25°46' 03".

Star Gazing for Beginners - Part III

Eyes on the Sky

If you haven't gone through the first and second parts, please have a look on it, Star Gazing for Beginners - Part I, Star Gazing for Beginners - Part II

Transcript:

Hi I’m David Fuller from the “Eyes on the Sky” video series. In this last Stargazing Basics video, we’ll learn how to easily measure distance in the sky, so you can find constellations or objects more easily either naked eye, with binoculars or telescopes. In our first video, we learned that a line called the meridian splits the sky into equal halves, from north to south. If we were to place a giant protractor in place of that line, it would appear as if the sky was 180 degrees from horizon to horizon. Although space is actually infinite, our eyes make the night sky appear like a “half sphere,” so for all practical purposes, it’s easier to think of the sphere. And though a sphere should technically be measure in radians, degrees is a concept people understand more readily and works for our purposes. So horizon to horizon is 180 degrees – that’s easy enough. And if we measured another large distance, from horizon to zenith, that would produce a right angle, or 90 degrees. Still pretty simple, right? But to measure smaller angles than that, we need a measuring tool. A ruler doesn’t work, because that would be for linear measurement, and holding a protractor to our eyes is a bit impractical. So what to do? Easy: Use your hands!

Check this out: Hold out your hand at arm’s length. Now spread your thumb and pinky as far away from each other as possible. If you look across your thumb and pinky, that distance is approximately 25 degrees. Don’t worry – this works for almost everyone. Don’t believe me? Look for the Big Dipper in the night sky. See the last two stars in the “Bowl” of the dipper? Draw a line through them, from the “bottom” of the bowl towards the top. Now hold your hand at that top star, along that line. The other side of your outstretched hand should be near Polaris, the north star, because that distance is NEARLY 25 DEGREES. But sometimes we need to measure smaller distances than 25 degrees. This time, hold up your forefinger and pinky, and stretch them out. The distance across them is about 15 degrees. This is about the distance from Orion’s belt to the star Aldebaran – this way – or the star Sirius, going this way. You can find these stars in the winter sky.

Img Credits : squarespace.com

For another smaller tool, hold up your fist. Across the top of your fist from side to side is about 10 degrees of sky. We can ‘calibrate” that by looking at FIND A GOOD CIRCUMPOLAR CALIBRATION. Two split that in half, now hold up these three fingers – this approximates 5 degrees of sky. Those two stars at the end of the Big Dipper are about 5 degrees from each other. Hold up your hand and see if your fingers match that. And lastly, the one degree tool. Simply hold up your pinky! This one amazes many people, because the actual angular distance across the Full Moon is only half of a degree. So holding your pinky at arm’s length, you can cover the WHOLE Moon! Of course, mixing and matching these can help you find even more – two hands like this can measure halfway across the 90 degrees of horizon to zenith, approximating 45 or 50 degrees or so. Use other combinations to create 30, 35 or 40 degrees, just by using two hands. 

But how will you know how far an angle is in the sky from a star chart? The declination lines will tell you degrees, but only in that direction. Try downloading the “Skymaps” all sky star charts each month. These charts are about 180 millimeters across. Though not terribly useful at the edges, as the sky diagrams are “stretched” there, you can use a simple ruler with millimeters on it to measure approximate angular distances in the sky, helping you “hop” from bright stars or well known constellations, to dimmer ones. Give it a try – it’s really easy, and works for just about everyone. Thanks for watching; I’m David Fuller. Keep your eyes on the sky and your outdoor lights aimed down by using dark sky friendly lighting fixtures, so we can all see, what’s up. 

Star Gazing for Beginners - Part II

Eyes on the Sky

If you haven't gone through the first part, please have a look on it, Star Gazing for Beginners - Part I

Transcript:

Hi I’m David Fuller from the “Eyes on the Sky” video series. Let’s look at another aspects of Stargazing Basics, this time, magnitudes of various objects. Magnitude is just a fancy way to describe the difference in brightness of objects we see in the night sky. And it’s not too hard to learn how it works, but let’s start with some history. The Greek astronomer Hipparchus developed the magnitude scale back in the 2-nd century BC, when he assigned the brightest stars a magnitude of “one” and the dimmest stars that of “six,” the in-between stars of 2, 3 , 4 and 5 magnitude assigned according to brightness. He assumed that the difference in brightness of stars was 2.512 times brighter than the next dimmest one. Taken across that full 6 magnitude scale, this meant that the brightest stars – the first magnitude ones - were 100 times brighter than the dimmest, 6-th magnitude ones. It also allows for a fairly easy way to determine other brightness differences: The difference from first to third magnitude is 6.3 times; first to fourth, 15.8, first to fifth , about 40 times.

This worked just fine until Galileo turned a telescope towards the heavens, and humans discovered there were a LOT more stars out there than just the first through sixth magnitude ones they could see naked eye. But what they did was just extrapolate the scale further. So much like golf or ERA in baseball, the lower the number, the brighter the star, and the higher the number, the dimmer the star. 11-th magnitude is 100 times dimmer than 6-th magnitude, and that 11-th magnitude star would also be 10,000 times dimmer than a first magnitude star. In the other direction, we have some objects that are brighter than first magnitude stars. Hipparchus actually fudged the numbers a bit; the star Sirius in the winter sky is definitely brighter than most other bright stars, and it shines at magnitude negative one point four. The planet Jupiter is brighter than that, often appearing at around magnitude negative 2, and Venus brighter still, typically around negative four. When objects are bright, they are denoted on star charts with larger dots; dimmer stars are usually given smaller dots. This helps us locate brighter objects in the sky more easily. But beyond the stars’ magnitudes is that of the Moon and Sun. 

The full Moon in the night sky shines at magnitude negative 12.7, and the Sun at magnitude negative 26.7! Those are both bright compared to starlight, but also a huge difference, even between themselves, as the Sun is 400,000 times brighter than the full Moon! Now everything we have discussed has been “visual magnitude,” meaning how bright or dim objects appear to our location on Earth. Another concept is “absolute magnitude,” used by astronomers to compare the relative brightness of objects when placed the same distance. But that is more complex than what we need to know for simple stargazing purposes. However, for visual magnitude, it helps to understand how it relates to other objects besides stars. Stars are point-like objects in the sky, so it is easy to assess their magnitude and brightness. But galaxies, star clusters and nebula are not quite as easy. So we look at their “integrated magnitude.” That’s a way of saying that the same magnitude is now spread out over a larger area. For small objects, that can mean it is something that will look brighter to us in telescopes. If the area if very large though – such as the galaxy M33 or the nebula M1, those objects may look very dim, relatively speaking. If possible, try to look for the surface brightness of an object; objects above a surface brightness of 11 or 12 can be very difficult to find from light polluted areas. 

That’s a quick overview of the magnitude scale, and how to understand it. Just remember the Sun and Moon have negative magnitudes and are the brightest visual magnitude objects, and lower numbers are dimmer stars and objects, and you’ll be in good shape! Thanks for watching; I’m David Fuller. Keep your eyes on the sky and your outdoor lights aimed down by using dark sky friendly lighting fixtures, so we can all see, what’s up. 

Star Gazing for Beginners - Part III

Know the Constellation - Orion

Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. Orion got its name from Greek Mythology. The story says, Orion was a giant hunter whom Zeus Placed among the stars as the Orion Constellation.

The brightest stars in Orion are Rigel and Betelgeuse. 

Located in the constellation Orion, Rigel is a Pulsating Variable Star. It is the brightest object in Orion,Rigel is approximately 863 light-years from earth. The sky location for Rigel is : RA 05h 14m 32s, Dec -09°47' 54"

Know the basics of sky gazing, Sky Gazing for Beginners - Part I

Betelgeuse is a Semi-regular Pulsating Star with distinctly reddish-tint. It is the second brightest star in Orion. It is also known by Betelgeuse's Bayer designation Alpha Orionis and is the ninth brightest star in the night sky. It is approximately 498 light-years from earth. Betelgeuse marks the upper right vertex of the Winter Triangle and center of the Winter Hexagon. Betelgeuse is expected to explode as a type II supernova. The sky location for Betelgeuse is : RA 05h 55m 10s, Dec +07°24' 26"

Credits : astrobob.areavoices.com

You can locate Sirius, the brightest star in the night sky, by using the belt of Orion. The belt points South East directly toward Sirius. Sirius is in the constellation of Canis Major and it is the fifth-nearest known star with a distance of just 8.7 light-years from earth.