NASA scientists have calculated that the Sun's atmosphere extends some 8
million kilometres above its surface. That's 20 times the distance
between the Earth and the Moon.
This figure, which is the equivalent of 12 solar radii, was determined using information from NASA's Solar Terrestrial Relations Observatory,
or 'STEREO'. STEREO is a solar observation mission that launched two
almost identical spacecraft in 2006 to orbit around the Sun and provide
stereoscopic imaging of its activities, including coronal mass ejections
and solar flares. In 2011, these two spacecraft managed to position
themselves exactly 180 degrees apart, which allowed scientists to view
the entire Sun all at once for the first time. Read more.
Physicists at the University of Queensland in Australia have used
photons - single particles of light - to simulate quantum particles
travelling through time and study their behaviour.
They were hoping to find out more about whether time travel would be
possible at the quantum level - a theory first predicted in 1991.
In the study, the researchers simulated the behaviour of a single
photon that travels through a wormhole and interacts with its older
self. This is known as a closed timelike curve - a closed path in space-time that returns to the same starting point in space but at an earlier time. Their study is published in Nature Communications. Read more.
Scientists from the
of Cambridge believe they have solved the longstanding mystery of
where superconductivity emerges in high-temperature superconductors.
Equipped with this knowledge, scientists may be able to tap into the
astronomical potential of these materials which could have
applications in a wide variety of technologies, from magnetic
levitating trains to supercomputers. Read more.
A legendary symbol of beauty adds romance to the early
morning skies this week, appearing along with some of the most elusive
of Earth’s neighboring worlds.
Venus, the Morning Star: Starting at dawn on
Tuesday, June 17, and for the rest of this week, look for the
diamond-like Venus to appear in the eastern sky. The brightest starlike
object in the morning sky, Venus will rise about 90 minutes before
dawn. The planet will hang about 10 degrees above the horizon within a
half hour before sunrise. Read more.
In January 2002,
astronomers discovered a massive explosion coming from V838
Monocerotis. They initially thought they were witnessing a supernova,
but after the initial flash of light began to dim (as expected), it
began to brighten again in infrared wavelengths at the beginning of
March. After that brightening faded, another one happened in April.
While astronomers were certain they weren’t witnessing a supernova,
they weren’t quite sure what it actually was. Read more.
Water is what gives
our planet its beautiful blue color and is critical for the existence
of life as we know it. Our entire planet is nicknamed after it - the
"blue planet", or "pale blue dot". A new study
led by geophysicist Steve Jacobsen of Northwestern University and
seismologist Brandon Schmandt from the University of New Mexico has
yielded evidence that vast oceans worth of water are tied up within
Earth’s mantle. The results are published in Science.
Foi descoberto um novo tipo de planeta extra-solar: um mega-planeta
rochoso que tem 17 vezes a massa da Terra e que poderá mudar a nossa
compreensão sobre o início do Universo. Como é muito maior do que as
super-Terras que têm vindo a ser encontradas à volta de outras estrelas
que não o nosso Sol, os cientistas puseram-lhe o nome do rei dos
monstros – Godzilla.
Este planeta de composição sólida rochosa, situado a
560 anos-luz de distância da Terra, foi detectado pelo telescópio
espacial Kepler, lançado em 2009 pela agência espacial norte-americana
NASA, anunciou a equipa responsável pela descoberta numa conferência de
imprensa durante uma reunião da Sociedade Americana de Astronomia, em
Boston (EUA). Ler mais.
The image, made by NASA's Hubble Space Telescope, shows the
Whirlpool Galaxy (also known as M51 and NGC 5194) in the optical
The image, made by NASA's Chandra X-ray Observatory,
shows the same galaxy in the x-ray waveband. The bright point sources in
the Chandra image correspond to binary stars made up of neutron stars
or black holes that are sucking material away from their companion
stars. The diffuse emission in Chandra image comes from interstellar
plasma that has been superheated by supernova explosions. More info.
In keeping with the theme of TED2008, professor Stephen Hawking asks
some Big Questions about our universe — How did the universe begin? How
did life begin? Are we alone? — and discusses how we might go about
NASA has recommitted itself to landing humans on Mars by 2035, but
has admitted that this is a project that will require the world to
work together. NASA's chief scientist Ellen Stofan gave a talk to the
Royal Institution in London a fortnight ago, and video of the talk
has now been released. "This is not something any one nation can
do on their own," Stofan said. "It's something that
humanity is going to do together."
Stofan sees a Mars mission as a crucial part of the quest to
answer the three questions she says turn up repeatedly in NASA's
goals: “Are we alone, how did we get here and how does the universe
work.” Mars is particularly important for answering the other two,
she argued, although she also talked about the potential for life on
Enceladus. Read more.
O objectivo deste blogue é partilhar ideias e materiais úteis para o estudo e para o ensino da Física e da Química. Destinatários: alunos, professores e outros eventuais interessados. Críticas e sugestões são bem-vindas. A autora reserva-se ao direito de apagar comentários despropositados.