Tag Archives: universe

Tellurium in the distance

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Nearly 13.7 billion years ago, the universe was made of only hydrogen, helium and traces of lithium — byproducts of the Big Bang. Some 300 million years later, the very first stars emerged, creating additional chemical elements throughout the universe. Since then, giant stellar explosions, or supernovas, have given rise to carbon, oxygen, iron and the rest of the 94 naturally occurring elements of the periodic table.

 

Today, stars and planetary bodies bear traces of these elements, having formed from the gas enriched by these supernovas over time. For the past 50 years, scientists have been analyzing stars of various ages, looking to chart the evolution of chemical elements in the universe and to identify the astrophysical phenomena that created them.

 

Now a team of researchers from institutions including MIT has detected the element tellurium for the first time in three ancient stars. The researchers found traces of this brittle, semiconducting alloy — which is very rare on Earth — in stars that are nearly 12 billion years old. The findingsupports the theory that tellurium, along with even heavier elements in the periodic table, likely originated from a very rare type of supernova during a rapid process of nuclear fusion. The researchers published their findings online in Astrophysical Journal Letters. …  (MIT-news)

Into the real world

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NASA’s chief climate scientist James E. Hansen built his career studying Earth’s atmosphere and modeling humans’ potential impacts on climate. Then he realized that laboratory work wasn’t enough. Hansen never thought his decision to study atmospheric models would lead to his arrest. But there he was in handcuffs this summer, protesting at the White House against a pipeline that would carry crude oil from Alberta’s oil sands to the Gulf of Mexico.

It wasn’t the first arrest, either. Hansen, who has directed NASA’s Goddard Institute for Space Studies for 31 years, earned the sobriquet “father of global warming” after testifying before Congress in 1988 on the dangers of global warming. He appeared again in 1989. Then he quietly returned to his work, turning aside television and media requests for the next 15 years because, as he said, “you have no time to do the science if you’re talking to the media.” … (Universe Today)

Our binary bits

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Craig Hogan believes that the world is fuzzy. This is not a metaphor. Hogan, a physicist at the University of Chicago and director of the Fermilab Particle Astrophysics Center near Batavia, Ill., thinks that if we were to peer down at the tiniest subdivisions of space and time, we would find a universe filled with an intrinsic jitter, the busy hum of static. This hum comes not from particles bouncing in and out of being or other kinds of quantum froth that physicists have argued about in the past. Rather Hogan’s noise would come about if space was not, as we have long assumed, smooth and continuous, a glassy backdrop to the dance of fields and particles. Hogan’s noise arises if space is made of chunks. Blocks. Bits. Hogan’s noise would imply that the universe is digital. (SciAm)

Planck. Not planking.

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The High Frequency Instrument on ESA’s Planck mission has completed its survey of the remnant light from the Big Bang. The sensor ran out of coolant on Saturday as expected, ending its ability to detect this faint energy.

“Planck has been a wonderful mission; spacecraft and instruments have been performing outstandingly well, creating a treasure trove of scientific data for us to work with,” said Jan Tauber, ESA’s Planck Project Scientist.

Less than half a million years after the Universe was created in the Big Bang 13.7 billion years ago, the fireball cooled to temperatures of about 4000 °C, filling the sky with bright, visible light. (ESA)

A refreshing drink on the Moon?

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New maps produced by the Lyman Alpha Mapping Project (LAMP) aboard NASA’s Lunar Reconnaissance Orbiter (LRO) reveal features at the Moon’s north and south poles in regions that lie in perpetual darkness. Developed by the Southwest Research Institute (SwRI), the LAMP instrument is sensitive on dim “starlight,” specifically the band of electro-magnetic frequencies emitted when hydrogen (which usually travels in pairs) is reduced to a single atom, usually when encountering other forms of radiation.
This Ly-α (Lyman-alpha) spectral line is peculiar to neutral hydrogen, the most basic and abundant element in the universe, is produced by light with a wavelength of 121.4 nm, a frequency below the narrow band of optical frequencies visible to the naked eye. By gathering data revealed by this all-pervasive indirect starlight LAMP can peer into so-called “permanently shadowed regions” (PSRs).
In repeated passes over the lunar poles using this method researchers have able to determine the presence of very fine structure, such as the likely porosity of lunar surface rock or the most likely textures of water frost in super-cold volatile traps, in permanent shadow from the Sun, and only in those places on the Moon not overwhelmed by direct or immediately indirect sunlight. (Lunar Pioneer)

 

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A distant Type-Ia

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These three images taken by NASA’s Hubble Space Telescope reveal the emergence of an exploding star, called a supernova.

Nicknamed SN Primo, the exploding star belongs to a special class called Type Ia supernovae, which are distance markers used for studying dark energy and the expansion rate of the universe. Type Ia supernovae most likely arise when white dwarf stars — the burned-out cores of normal stars — siphon too much material from their companion stars and explode. … (HubbleSite)

Crowdsourcing for ET

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The most profound question asked by mankind is: are we alone? So the second most profound question must be: where should we look if we’re not alone?

Now, two prominent scientists have published a paper suggesting that although we have an entire universe to seek out the proverbial alien needle in a haystack, perhaps looking in our own backyard would be a good place to start.

Paul Davies and Robert Wagner of Arizona State University have suggested a crowd-sourcing effort to find artificial structures on the moon. After all, lunar missions like NASA’s Lunar Reconnaissance Orbiter are returning some dazzling, high-resolution imagery of the moon’s surface. If aliens have been there, perhaps we could spot evidence of their presence.

“Although there is only a tiny probability that alien technology would have left traces on the moon in the form of an artifact or surface modification of lunar features, this location has the virtue of being close, and of preserving traces for an immense duration,” Davies and Wagner say in their paper published in the journal Acta Astronautica. (Discovery)