Skip to main content

Home/ Astronomy/ Group items tagged by

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Sandra Flores

Fifth ATV's Georges Lemaître - 1 views

The fifth and final current proposed Automated Transfer Vehicle (ATV) of the European Space Agency will carry the name "Georges Lemaître". The Belgian theologian and astrophysicists is considered t...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Janos Haits

Tau Zero Foundation - 0 views

www.tauzero.aero

tau zero foundation science astronomy space cosmology planetary galactic physics

shared by Janos Haits on 09 Feb 11 - Cached
  • Janos Haits on 09 Feb 11
     
    The Tau Zero Foundation is a volunteer group of scientists, engineers, entrepreneurs, and writers who have agreed to work together toward practical interstellar flight and to use this quest to teach you about science, technology, and our place in the universe. By posting the latest developments and unfinished advancements here, we give students the starting materials to begin their own discoveries. By showing both how daunting and incredible this challenge is, we hope to increase attention on protecting the habitability of Earth while planning journeys into the galaxy. By reaching for the stars we will create benefits every step of the way.
Todd Suomela

[0904.0402] A thermodynamic basis for prebiotic amino acid synthesis and the nature of ... - 0 views

arxiv.org/0904.0402

arxiv astrobiology exobiology astronomy biology

shared by Todd Suomela on 07 Apr 09 - Cached
Andres Ruiz liked it
  • Todd Suomela on 07 Apr 09
     
    Of the twenty amino acids used in proteins, ten were formed in Miller's atmospheric discharge experiments. The two other major proposed sources of prebiotic amino acid synthesis include formation in hydrothermal vents and delivery to Earth via meteorites. We combine observational and experimental data of amino acid frequencies formed by these diverse mechanisms and show that, regardless of the source, these ten early amino acids can be ranked in order of decreasing abundance in prebiotic contexts. This order can be predicted by thermodynamics. The relative abundances of the early amino acids were most likely reflected in the composition of the first proteins at the time the genetic code originated. The remaining amino acids were incorporated into proteins after pathways for their biochemical synthesis evolved. This is consistent with theories of the evolution of the genetic code by stepwise addition of new amino acids. These are hints that key aspects of early biochemistry may be universal.
Janos Haits

Starry Messenger - 0 views

www.hps.cam.ac.uk/...starrymessenger.html

science research technology Education astronomy space planetary universe physics solar

shared by Janos Haits on 28 May 12 - Cached
  • Janos Haits on 28 May 12
     
    The Starry Messenger is Phase I of the Electronic History of Astronomy developed in the Whipple Museum of the History of Science and the Department of History and Philosophy of Science. This phase was directed by Dr Sachiko Kusukawa and Dr Liba Taub, and supported by funding from Trinity College, Cambridge. Dr David Chart was the Project Manager.
Todd Suomela

SAO/NASA ADS: ADS Home Page - 0 views

www.adsabs.harvard.edu

astronomy astrophysics catalog library reference research sts

shared by Todd Suomela on 05 Jun 08 - Cached
  • Todd Suomela on 05 Jun 08
     
    The SAO/NASA Astrophysics Data System (ADS) is a Digital Library portal for researchers in Astronomy and Physics, operated by the Smithsonian Astrophysical Observatory (SAO) under a NASA grant. The ADS maintains three bibliographic databases containing more than 6.9 million records: Astronomy and Astrophysics, Physics, and arXiv e-prints. The main body of data in the ADS consists of bibliographic records, which are searchable through highly customizable query forms, and full-text scans of much of the astronomical literature which can be browsed or searched via our full-text search interface. Integrated in its databases, the ADS provides access and pointers to a wealth of external resources, including electronic articles, data catalogs and archives. We currently have links to over 7.6 million records maintained by our collaborators.
Todd Suomela

Jupiter gets another cosmic punch, shows new bruise - Ars Technica - 0 views

arstechnica.com/...mic-punch-shows-new-bruise.ars

astronomy planetary Jupiter photography amateur

shared by Todd Suomela on 23 Jul 09 - Cached
  • Todd Suomela on 23 Jul 09
     
    Over the weekend, Jupiter was apparently struck by an unknown object, probably a comet or an asteroid. The discovery was made by Anthony Wesley in Australia, an amateur astronomer well-known in both the amateur and professional astronomy communities.
Sandra Flores

Surface and core of the Earth in its sights - 0 views

Surface and core of the Earth in its sightsOn September 10, the Russian Plesetsk cosmodrome to be brought from the ESA GOCE satellite into orbit to determine the gravitational field and the referen...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

Back on The Ground - 0 views

Furnace starts trial operationThe German ESA astronaut Alexander Gerst is now back on the ground, the commissioning of an assembled by him on the ISS furnace for experiments in materials science, h...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

First images of the comet - 0 views

Send Mars probes first images of the cometOn Sunday evening, the comet C / 2013 A1 (Siding Spring) is over flown at a distance of almost 140,000 kilometers on Mars. All active Mars probes have surv...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

Surface and core of the Earth in its sights - 0 views

Surface and core of the Earth in its sightsOn September 10, the Russian Plesetsk cosmodrome to be brought from the ESA GOCE satellite into orbit to determine the gravitational field and the referen...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Sandra Flores

Back on The Ground - 0 views

Furnace starts trial operationThe German ESA astronaut Alexander Gerst is now back on the ground, the commissioning of an assembled by him on the ISS furnace for experiments in materials science, h...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Sandra Flores

First images of the comet - 0 views

Send Mars probes first images of the cometOn Sunday evening, the comet C / 2013 A1 (Siding Spring) is over flown at a distance of almost 140,000 kilometers on Mars. All active Mars probes have surv...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Astro Biology

NASA Research Alien Life - 0 views

www.astrobio.net/...eline-future-alien-life-search

alien life news on other planets of aliens

shared by Astro Biology on 15 Sep 14 - No Cached
  • Astro Biology on 15 Sep 14
     
    Astronomers searching the atmospheres of alien worlds for gases that might be produced by life can't rely on the detection of just one type.
  • Astro Biology on 15 Sep 14
     
    Astronomers searching the atmospheres of alien worlds for gases that might be produced by life can't rely on the detection of just one type.
Kalyan Roy

Why Are Quark Stars So Strange? : Discovery News - 1 views

news.discovery.com/...re-quark-stars-so-strange.html

Astronomy

shared by Kalyan Roy on 20 Jan 10 - Cached
  • First things first, neutron stars, quark stars and black holes are all born via the same mechanism: a supernova. But each of the three are progressively more massive, so they originate from supernovae produced by progressively more massive stars. So, what if a star exploded, producing something a little too massive to be called a neutron star? Well, neutron stars resist collapsing under their own gravitational pull by a characteristic of matter known as neutron degeneracy. This produces an outward force called neutron degeneracy pressure. What if the neutron star born after a supernova is too massive for this neutron degeneracy pressure to hold up against the neutron star's own gravity? In this case, it's up to the quarks that make up the neutrons to take over, preventing the body from collapsing any further. Single neutrons are composed of three quarks (two "down" quarks and one "up" quark). When quark degeneracy pressure kicks in, a quark star may be produced; the free "up" and "down" quarks get converted into "strange" quarks. Therefore, a quark star (also known as a "strange star") is made up of strange matter.
  • Using what we know from the Standard Model of particle physics, a massive quark star may have enough gravitational energy to start 'burning' strange matter. The quarks inside the core of the quark star may be abused so badly by gravitational pressure that the quarks will be converted into pure energy and neutrinos.
  • The fascinating thing with this scenario is that the quark star matter will be so dense that even the neutrinos cannot escape. However, this release of energy and generation of neutrinos creates an outward pressure countering the relentless inward gravitational pull.
  • ...2 more annotations...
  • Dai calls this extreme strange matter-burning quark star an "electroweak star"
  • Saving the best till last, the electroweak star's core would therefore be as extreme as the universe was only 10-10 seconds (that's 0.0000000001 seconds) after the Big Bang. These extreme objects would be like mini-Big Bang laboratories, maintaining a pressure where the electromagnetic and weak forces are so intertwined, they cannot be distinguished.
Todd Suomela

Guest Post: Evalyn Gates on Cosmic Magnification (or - Invasion of the Giant Blue Space... - 0 views

blogs.discovermagazine.com/...f-the-giant-blue-space-amoebas

astronomy astrophysics gravity-lens physics science gravity methods

shared by Todd Suomela on 19 Jul 09 - Cached
  • This is not just a pretty picture, however – the image packs a lot of scientific information. The authors extract the mass distribution in the cluster (which has implications for cosmological models), measure the mass-to-light ratio of the bright galaxy in the center of the cluster, and use the magnifying power of the lens to search for even more distant galaxies. The basic idea is to construct a model of the lens, starting with the cluster galaxies and a dark matter halo; then refine the model to reproduce the multiple images that are seen. Using this refined model it’s possible to predict the location of additional images of a given source, and to identify regions of high magnification that can then be examined for multiple images of other sources. Any additional images that are found can be used to further refine the model and so on.
  • This galaxy has been lensed by the warp in spacetime created by the cluster. Light from the galaxy, which lies almost directly behind the center of the cluster but much farther away from us, travels along several curved paths through the cluster lens, producing multiple magnified images of the galaxy. The inset box shows a computer generated model of the unlensed source galaxy, enlarged by a factor of four so that the details, including the spiral arm structure, are visible. Without the lensing power of the cluster, we would see this galaxy as a single small blue smudge. In general, lensing will both magnify and distort (shear) images of a background source. This lens is fairly unique in that we see large but relatively intact images of the spiral galaxy, which implies that the mass distribution in the central region of the cluster must be nearly uniform.
Sandra Flores

Star Formation - 0 views

Heated gas stream at a cool star formation?In the inner regions of a galaxy cluster, astronomers found by Michael McDonald from the Massachusetts Institute of Technology in the USA further evidence...

stars cosmos astronomy

started by Sandra Flores on 02 Nov 14 no follow-up yet
Sandra Flores

Strange stars on the heel - 0 views

Strange stars on the heelA new star strange lurks perhaps in our galaxy - and an astrophysicist at the Weizmann Institute is close on the track. Prof. Vladimir Usov from the Weizmann Institute...

started by Sandra Flores on 05 Jan 15 no follow-up yet
Sandra Flores

Strange stars on the heel - 0 views

Strange stars on the heelA new star strange lurks perhaps in our galaxy - and an astrophysicist at the Weizmann Institute is close on the track. Prof. Vladimir Usov from the Weizmann Institute...

started by Sandra Flores on 09 Jan 15 no follow-up yet
Janos Haits

The Blue Marble - Wikipedia, the free encyclopedia - 2 views

en.wikipedia.org/Blue_Marble

blue marble planet earth earthsky Science space planetary universe Astronomy

shared by Janos Haits on 15 May 12 - No Cached
  • Janos Haits on 15 May 12
     
    The Blue Marble is a famous photograph of the Earth, taken on December 7, 1972, by the crew of the Apollo 17 spacecraft, at a distance of about 45,000 kilometres (28,000 mi).[1]
1 - 20 of 72 Next › Last »
Showing 20▼ items per page