Category Archives: Understand Science
Scientists have been reconstructing the history of the moon by scouring its surface, mapping its mountains and craters, and probing its interior. What are they learning about our own planet’s beginnings? Decades ago, we sent astronauts to the moon as a symbol of confidence in the face of the great cold war struggle. Landing on the moon was a giant leap for mankind. But it’s what the astronauts picked up from the lunar surface that may turn out to be Apollo’s greatest legacy.
When the astronauts of Apollo stepped out of their landing craft, they entered a world draped in fine sticky dust, strewn with rocks, and pocked with craters. They walked and rambled about, picking up rocks that they packed for the return flight. Back in earth-bound labs, scientists went to work probing the rocks for clues to one of the most vexing questions in all of science. Where did the moon come from? The answer promised to shed light on an even grander question. Where did Earth come from? And how did it evolve into the planet we know today?
The nature of the moon began to come into focus four centuries ago. Galileo Galilei had heard of an instrument built by Dutch opticians capable of “seeing faraway things as though nearby.” Galileo, in many ways the first modern scientist, saw this new instrument as a tool to help settle a long standing question. What was the nature of the heavens, and how did the world of men fit within it? To some philosophers, the moon was a perfect, crystalline sphere of divine substance, free of Earth’s imperfections. Galileo, with his telescope, saw a more familiar reality. He noted mountains and valleys on the moon, features like those of Earth.
The astronauts of Apollo lifted off on a series of missions to get a close up look at the moon and perhaps settle the debate. Because there’s no atmosphere there, the astronauts entered landscapes that are nearly frozen in time. They could scour the lunar surface for evidence of events going back almost to the time of its birth.
Indeed, eons of impacts had opened up the Moon’s interior, leaving a wealth of information strewn about their landing sites. Scientists had already noticed that some large old craters were surrounded by concentric rings. You can see one of the most pronounced examples in this image of the Mare Orientale, captured recently by NASA’s Lunar Reconnaissance Orbiter, or LRO. The colors show differences in elevation.
The old view was that the impact had melted the rock below. A newer view held that the impactor had actually splashed down on a molten surface. That gave rise to the radical notion that, early in its history, the moon’s surface was covered in a vast ocean of magma. When the astronauts arrived, they found relatively light rocks known as anorthosites. Their presence suggested that heavier material had sunk toward the moon’s interior, forcing lighter material to the surface. The rocks they brought back were found to be strikingly similar to those on Earth, in part because they share forms of oxygen, called isotopes, that scientists regard as “blood types” for solar system bodies. Then there was this. The moon appeared to be completely, utterly, dry, with no evidence that water was ever present on its surface.
NASA’s Orion spacecraft launched successfully atop a United Launch Alliance Delta IV Heavy rocket Dec. 5 at 7:05 a.m. EST from Space Launch Complex 37 at Cape Canaveral Air Force Station in Florida. Orion’s Exploration Flight Test-1 (EFT-1), is the first flight test for NASA’s new deep space capsule and is a critical step on NASA’s journey to Mars. The 4.5 hour flight is scheduled to conclude with the splashdown of Orion in the Pacific Ocean.
The testing of ORION – NASA’s Deep Space Exploration Spacecraft has been postponed once again. This video explains in detail NASA’s new deep space exploration spacecraft called Orion which will take humans farther into space than ever before including landing on an asteroid, the moons of Mars, and Mars itself.
Stripping away the Milky Way’s stars, planets, rocks and dust reveals a massive black hole lurking just 26,000 light years from Earth.
It is commonly theorized that the universe began with the Big Bang 13.7 billion years ago. But since we can only see as far as light has traveled in that time, we can’t actually make out the edge of the universe. Could it be that the universe is infinite? Is there any way to find out what the shape of the universe really is? Can we find the edge, discover what might lie beyond it, and perhaps even discover a universe next to ours? Narrated by Morgan Freeman
14th Isaac Asimov Memorial Debate conducted by the American Museum of Natural History hosted by the Director of the Hayden Planetarium and Celebrity Astrophysicist Neil deGrasse Tyson. He welcomes a distinguished panel of scientist to discuss and debate the Existence of Nothing. Panelists include Richard Gott, Lawrence Krauss, Eve Silverstein, Jim Holt and Charles Seife. This is a great debate watch till the end.
The details in this video are as of 2009. I have posted it only for you to compare the sizes and get an idea of scale. The largest star identified as of now is UY Scuti. Click here for the complete list from Wikipedia.
VY Canis Majoris (VY CMa) is a red hypergiant star located in the constellation Canis Major. With a size of 2600 solar radii, it is the largest known star and also one of the most luminous known. It is located about 1.5 kiloparsecs (4.6×1016 km) or about 4,900 light years away from Earth. Unlike most stars, which occur in either binary or multiple star systems, VY CMa is a single star. It is categorized as a semiregular variable and has an estimated period of 6,275,081 days, or just under 17,200 years.
Antares is a red supergiant star in the Milky Way galaxy and the sixteenth brightest star in the nighttime sky (sometimes listed as fifteenth brightest, if the two brighter components of the Capella quadruple star system are counted as one star). Along with Aldebaran, Spica, and Regulus it is one of the four brightest stars near the ecliptic. Antares is a variable star, whose apparent magnitude varies from +0.9 to +1.8.
The Pistol Star is a blue hypergiant and is one of the most luminous known stars in the Milky Way Galaxy. It is one of many massive young stars in the Quintuplet cluster in the Galactic Center region. The star owes its name to the shape of the Pistol Nebula, which it illuminates. It is located approximately 25,000 light years from Earth in the direction of Sagittarius. It would be visible to the naked eye as a fourth magnitude star, if it were not for the interstellar dust that completely hides it from view in visible light.
Rigel (β Ori / β Orionis / Beta Orionis) is the brightest star in the constellation Orion and the sixth brightest star in the sky, with visual magnitude 0.18. Although it has the Bayer designation “beta”, it is almost always brighter than Alpha Orionis (Betelgeuse).
Aldebaran (α Tau, α Tauri, Alpha Tauri) is an orange giant star located about 65 light years away in the zodiac constellation of Taurus. With an average apparent magnitude of 0.87 it is the brightest star in the constellation and is one of the brightest stars in the nighttime sky. The name Aldebaran is Arabic (الدبران al-dabarān) and translates literally as “the follower”, presumably because this bright star appears to follow the Pleiades, or Seven Sisters star cluster in the night sky. This star is also called the Bull’s Eye because of its striking orange color and its location in the bull’s head shaped asterism. NASA’s Pioneer 10 spacecraft, which flew by Jupiter in 1973, is currently traveling in the direction and will reach it in about two million years.
Arcturus (α Boo / α Boötis / Alpha Boötis) is the brightest star in the constellation Boötes. With a visual magnitude of −0.05, it is also the third brightest star in the night sky, after Sirius and Canopus. It is, however, fainter than the combined light of the two main components of Alpha Centauri, which are too close together for the eye to resolve as separate sources of light, making Arcturus appear to be the fourth brightest. It is the second brightest star visible from northern latitudes and the brightest star in the northern celestial hemisphere. The star is in the Local Interstellar Cloud.
Pollux (β Gem / β Geminorum / Beta Geminorum) is an orange giant star approximately 34 light-years from the Earth in the constellation of Gemini (the Twins). Pollux is the brightest star in the constellation, brighter than Castor (Alpha Geminorum). As of 2006, Pollux was confirmed to have an extrasolar planet orbiting it.
Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name Sirius is derived from the Ancient Greek Σείριος. The star has the Bayer designation α Canis Majoris (α CMa, or Alpha Canis Majoris). What the naked eye perceives as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B.
The Sun is the star at the center of the Solar System. The Sun has a diameter of about 1,392,000 kilometres (865,000 mi) (about 109 Earths), and by itself accounts for about 99.86% of the Solar System’s mass; the remainder consists of the planets (including Earth), asteroids, meteoroids, comets, and dust in orbit. About three-fourths of the Sun’s mass consists of hydrogen, while most of the rest is helium.
The Universe in a Nutshell: The Physics of Everything
Michio Kaku, Henry Semat Professor of Theoretical Physics at CUNY
What if we could find one single equation that explains every force in the universe? Dr. Michio Kaku explores how physicists may shrink the science of the Big Bang into an equation as small as Einstein’s “e=mc^2.” Thanks to advances in string theory, physics may allow us to escape the heat death of the universe, explore the multiverse, and unlock the secrets of existence. While firing up our imaginations about the future, Kaku also presents a succinct history of physics and makes a compelling case for why physics is the key to pretty much everything.
New telescopes come with a couple different types of inexpensive finders – magnifying and non-magnifying ones. In this video, David Fuller of “Eyes on the Sky” takes the viewer through the various types of basic finders, highlighting the benefits and drawbacks of each so the viewer can make a better educated decision when purchasing a new telescope. Also covered is how to align a finderscope with the main telescope, with a visual demonstration of how it might look for the viewer.
Barlow lenses are an inexpensive – and often effective – way to increase the magnification and eyepiece collection of amateur astronomers. In this video, David Fuller of “Eyes on the Sky” takes the viewer through the various types, caveats and benefits with using them, as well as what to look for when shopping for one.
This video about the basics of telescopes discusses field of view, in particular, the difference between apparent field of view (AFOV) and telescopic field of view (TFOV). With an explanation of the math used to calculate these plus various examples of the calculations and visuals, the viewer can finish this video with a more complete understanding of this concept that is often confusing to beginning amateur astronomers who are new to telescopes.
Hosted by David Fuller of “Eyes on the Sky,” this video goes over the various sizes and types of basic eyepieces for many amateur telescopes. The three most common eyepiece barrel diameters are discussed, as well as the types of lens configurations which determine how well the eyepiece forms an image for the user – including the concept of eye relief which can matter a lot to those who wear eyeglasses. Discussed are Huygens, Ramsden, Kellner, RKE, Modified Achromat, Plossl and some advanced designs, plus some information about anti-reflection coatings. An excellent primer for anyone wanting to understand more about telescope eyepieces.
Hosted by David Fuller of “Eyes on the Sky,” this video discusses the basics of telescope magnification and focal ratio. Each concept is covered, guiding the viewer through how to calculate magnification of a telescope and eyepiece combination, and how to determine the focal ratio of a given telescope. An excellent primer for anyone wanting to understand more about telescopes.
Many of you may be wondering how the MOM and MAVEN missions to Mars are different. If you had questions like I had about this please follow the link below to the Planetary Society Blog where Planetary Scientist Emily Lakdawalla explains the difference very clearly along with the “Basics of Space Flight” by David Doody . It is a very good online resource for knowing about Space flight. You can also download the book Basics of Space Flight and read it.
In this Documentary you will understand the importance of Orbits of heavenly bodies and the speciality of Earth’s Orbit.
After 2 years and nearly 9 kilometers of driving, NASA’s Mars Curiosity has arrived at the base of Mount Sharp to begin a whole new phase of exploration.
On June 30, 2004 (PDT), as mission controllers at NASA’s Jet Propulsion Laboratory held their collective breath, the international Cassini-Huygens mission successfully arrived in orbit around Saturn. NASA’s Cassini spacecraft delivered the European Space Agency’s Huygens probe to Titan in early 2005. Cassini completed its four-year primary mission in 2008 and went on to perform dozens more flybys of Titan, Enceladus and Saturn’s other icy moons through its 10th anniversary in 2014. The mission may continue through 2017.
The Harvest Moon has some interesting aspects to it; how it rises differently from other full Moons, and how we often perceive it as it rises. Learn about that and more as Dave shares insight into this “Super Moon” visible as a Harvest Moon, and why the size isn’t quite what it seems (even if it’s “super” this month). See what’s up in the night sky every week with “Eyes on the Sky” videos, astronomy made easy.
Many of you have been asking about the position of Pluto as a Planet. Here is the information from the IAU (International Astronomical Union) below. Click the link below to go to the Pluto Page and know more about how they decide on a Planet in our solar System
In this video Robert gives you our top five tips to coax the best possible views of planets regardless of the cost or quality of your telescope.
It doesn’t matter if your telescope costs tens, or thousands : it always makes sense to try to get the best views you possibly can when observing planets. And sometimes improving the view involves no more than selecting the best site available to you to set up the telescope or using the telescope within its ideal power range — this video will give you the information you need to consistently get the best views of planets with your telescope.
Presented by Robert J Dalby FRAS
Produced by A.R.B Media Productions for Astronomy and Nature TV
Robert J Dalby FRAS of The Astronomy and Nature Centre explains how to observe planets.
Getting consistently good views of planets and other targets in the night sky can seem a bit hit and miss to the new telescope user. In this video look at a couple of the most basic variables that can affect the resolution and detail seen in planetary observation. Learn how and when to address the target to optimise image quality with any telescope.
Lets remind ourselves about some of the concepts we learnt in our camp:
I know all of you are busy preparing for your terminal exams, so I am posting only videos of shorter duration. On Oct 19th 2010, astronomers announced the measurement of a redshift of 8.6 for one of the galaxies in the Ultra Deep Field. Here’s the news release from ESO’s website. This is old news but relevant to understanding the Cosmos.
The question of what caused the Big Bang is one of the most difficult facing humanity. We may never find an answer, and even if we do, we probably won’t understand it. It’s difficult to imagine an event occurring without a cause, and yet, that is precisely the prospect we are faced with when it comes to this question.