Telescope Thursday: “Cool” Facts About Webb Telescope
Published March 31, 2011
NASA Astrophysicist Amber Straughn demonstrates the cold environment where the Webb telescope will be by dipping flexible rubber surgical tubing into liquid nitrogen in the video. (Click Image to play the video) Credit: NASA
In a 4 minute video produced at NASA’s Goddard Space Flight Center in Greenbelt, Md., astrophysicist Amber Straughn takes you on a quick journey of facts and images to explain what the Webb will tell us about the cosmos.
Amber provides some amazing images of the Hubble and phenomena that it has seen while answering the question, how will Webb improve on what Hubble has seen? Amber tells viewers how Webb’s use of infrared light is going to reveal a lot more than astronomers have ever seen before. She also explains how the Webb telescope can see farther back in space and time, and compares the size of the Webb and Hubble primary mirrors to the height of a person.
What’s so cool about the Webb telescope? Amber demonstrates just how cold the temperatures of space are where Webb will orbit (over 1 million miles from the Earth) by dipping flexible rubber surgical tubing into liquid nitrogen. At room temperature, nitrogen is a gas; but is a liquid at very cold temperatures – below -321 Fahrenheit (F)/-196 Celsius (C) similar to what the Webb will experience and can instantly change the structure of the tubing, and Amber proves this by smashing it like glass!
First Image Ever Obtained from Mercury Orbit
Published March 29, 2011
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
At 5:20 am EDT on Mar. 29, 2011, MESSENGER captured this historic image of Mercury. This image is the first ever obtained from a spacecraft in orbit about the Solar System’s innermost planet. Over the subsequent six hours, MESSENGER acquired an additional 363 images before downlinking some of the data to Earth. The MESSENGER team is currently looking over the newly returned data, which are still continuing to come down.
Source:NASA Image of the Day Gallery
Meteorites May Have Delivered First Ammonia for Life on Earth
Published March 28, 2011Anne Minard at Universe Today writes:
Researchers have teased ammonia of a carbon-containing meteorite from Antarctica, and propose that meteorites may have delivered that essential ingredient for life to an early Earth.
The results appear today in the Proceedings of the National Academy of Sciences, and add to a growing body of evidence that meteorites may have played a key role in the development of life here. The NASA graphic at left was released just last month, when researchers reported that meteorites may have also delivered Earth’s first left-hand amino acids.
Lead author Sandra Pizzarello, of Arizona State University, and her colleagues note in the new paper that carbonaceous chondrites are asteroidal meteorites known to contain abundant organic materials.
“Given that meteorites and comets have reached the Earth since it formed, it has been proposed that the exogenous influx from these bodies provided the organic inventories necessary for the emergence of life,†they write.
A Renazzo stony meteorite. Credit: NASA
Next, the researchers analyzed the nitrogen atoms within the ammonia and determined that the atomic isotope did not match those currently found on Earth, eliminating the possibility that the ammonia resulted from contamination during the experiment. Researchers have struggled to pinpoint the origin of the ammonia responsible for triggering the formation of the first biomolecules on early Earth. The authors suggest that now, they may have found it.
“The findings appear to trace CR2 meteorites’ origin to cosmochemical regimes where ammonia was pervasive, and we speculate that their delivery to the early Earth could have fostered prebiotic molecular evolution,†they write.
Source(s): Pizzarello et al., Abundant ammonia in primitive asteroids and the case for a possible exobiology. , Universe Today – (used with permission)
Astronomy Question: Speed of Celestial Bodies?
Published March 24, 2011John asks:
According to Hubble’s discovery, the galaxies are moving away from each other at a growing speed, but I read that the speed of matter after the BB was enormous and then with time it has been slowing down. Isn’t this a contradiction?
Great question John!
Let me start by separating your question into two parts, matter and space.
Special Relativity as postulated by Einstein in 1905, states no matter (or information) can travel faster than light.
Hubble’s (The Astronomer, not the space telescope), work in Astronomy provided some of the early foundation for cosmology as we know it. Hubble’s discoveries led to our understanding, as you pointed out, of an “expanding” universe.
What current theories state is that while matter/information/light cannot travel faster than the speed of light, “space” itself is not bound by this restriction. I believe there may also be some theories that state for a brief, brief period just after the big bang, there was matter that did travel faster than light speed, but I’ll be the first to admit that I’m not a Cosmologist.
The analogy used commonly (I’ve heard it on many science shows and read in many articles) is raisin bread. Consider the raisins akin to galaxies and the “dough” space between them. While the bread bakes, the dough rises/expands, so while the raisins themselves aren’t moving, the “space” between them is!
You can actually use the Hubble constant and the speed of light to determine at what distance between two galaxies must have in order for the galaxies to be moving apart faster than the speed of light. Hint: a bit over 4,000 Megaparsecs ( One Parsec is 3.26 light years). To give you an idea of scale, the observable universe has a radius of about 14 Gigaparsecs (about 45 billion light years). So, while our universe is estimated to be just over 13 billion years old, cosmic expansion has put our observable radius to the above-mentioned 45 billion light year range.
With regards to speeding up or slowing down, dark energy is theorized to be what is responsible for the expansion of the universe to be accelerating.
Hope this helps shed some light (pardon the pun) on the physics of the expanding universe.