Flying over planet Earth

Unequal weights fall with the same speed in a vacuum

"In his 1638 Discorsi Galileo's character Salviati, widely regarded as largely Galileo's spokesman, held that all unequal weights would fall with the same finite speed in a vacuum. (...) Galileo proposed that a falling body would fall with a uniform acceleration, as long as the resistance of the medium through which it was falling remained negligible, or in the limiting case of its falling through a vacuum."

Source: http://en.wikipedia.org/wiki/Galileo_Galilei

Wonders of the Universe

No APOD de hoje está um vídeo muito interessante que nos leva numa viagem pelos objectos celestes do nosso Cosmos. O vídeo foi criado pela BDH e a música por Timo Baker.

Link para o APOD:  http://apod.nasa.gov/apod/ap110418.html

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Today's APOD is not a picture but it is an amazing video which takes us in a journey throughout the Cosmos. The video was produced by  BDH and the music was composed by Timo Baker.

Link to APOD:  http://apod.nasa.gov/apod/ap110418.html

AAPOD 07/04/11: Biggest Moonrise in almost 20 years

É com agrado que vejo mais uma foto minha como AAPOD!
Link permanente:
http://astronomy.fm/aapod/2011-04-07_Biggest-Moonrise-in-almost-20-years.html
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I am glad that "my Super MoonRise" is today's AAPOD!
Permanet link:
http://astronomy.fm/aapod/2011-04-07_Biggest-Moonrise-in-almost-20-years.html

NASA Announces 1235 Planet Candidates

NASA's Kepler mission has discovered its first Earth-size planet candidates and its first candidates in the habitable zone, a region where liquid water could exist on a planet's surface. Five of them are Earth-like. The findings increase the number of planet candidates identified by Kepler to-date to 1235. 170 stars show evidence of multiple planetary candidates 

Source:  http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=98

LPOD: 20/Mar/2011 - Supermoonrise

LPOD: 20/Mar/2011

I am glad to see that my image sequence of the supermoonrise was selected to be today's LPOD (with Damian Peach's image too). It's "my" second LPOD (this was the first). The aparent diameter of this (almost) perigee moon (only 1h05min apart) was about 33.5'! Very impressive!

Here it is the permanet link to LPOD of 20/Mar/2011:
http://lpod.wikispaces.com/March+20%2C+2011


PS: Check  also Supermoon Photo Gallery from APOD's forum!

Biggest Moon in almost 20 years!

This animated (click in the pictures to start the animation) GIFs shows the "biggest moonrise" in almost 20 years! The moon had reached the perigee just 1h05min before I took the pictures. Prime focus in 8" f/5 reflector and Canon 1000D.

 

Color

B&W

Color inverted

BW inverted

This video from NASA explains the phenomenon:

Amazing Storm on Saturn

This image taken by the Cassini (24/12/10) spacecraft shows the giant storm on Saturn. At it's current size the storm should be visible even with mid-sized amateur telescopes (in good seeing conditions). Also take a look at the image of the storm taken from Earth by Anthony Wesley: http://spaceweather.com/swpod2010/28dec10/wesley1.jpg?PHPSESSID=92s2crjldso0ucu0leq0a27pk6

365 Days of Astronomy Podcast: Life in the Universe: Odds and Expectations

Hi everyone,

Today (yesterday actually, 4th October) my podcast was transmited worldwide through the  365 Days of Astronomy Podcast website (http://365daysofastronomy.org/). The title is "Life in the Universe: Odds and Expectations".

You can listen to it in: http://365daysofastronomy.org/2010/10/04/october-4th-life-in-the-universe-odds-and-expectations/ by clicking in dowload.

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(!you can listen to it in the link above!)

Transcript:

 

Hi, I am André Gonçalves from Vieira do Minho, Portugal. Today I will talk about life on Earth and the possibilities of life arising in other worlds far away from ours, as well as the basic conditions a planet must have in order to support life. I will try to reach several topics and make you think, wonder and even speculate about extraterrestrial life.

The most accepted theory for the origin of life on Earth is called “The Primordial Soup Theory” which suggests that life began in an ancient ocean filled with organic compounds and a primitive atmosphere mainly constituted by hydrogen and nitrogen. The heat, the ultraviolet radiation and the abundant lightings triggered chemical reactions that formed amino-acids, the building blocks of life that make up proteins.

RNA is generally assumed to be the earliest self-replicating molecule, which eventually led to the first unicelular organism. Several millions of years later, photosynthesizing cyanobacteria evolved and the concentration of oxygen in Earth’s primitive atmosphere rose. The origin of multicellularity may have occurred from symbiosis of single celled organisms, each with different roles in the colonies.

But these were only the first steps. Then, life exploded on Earth: plants, animals, fungi, etc emerged and evolved for millions of years until today.

Nowadays, our ‘blue planet’ is full of life and millions of different species inhabit our planet. Why Earth is really good for life? Well, there are lots of reasons but I’ll try to focus on the most important ones. Liquid water is obviously an important condition, and almost all the life forms on Earth depend on it. Also, it is a solvent and allows the interaction of organic molecules (in ice the molecules are trapped and can’t interact with each other; in water vapor the molecules are far away from each other and the interaction is difficult). Polarity is another property of water which makes it an “universal solvent”. Water can dissolve salts, acids, sugars, as well as gases. Most cell components including proteins, polysaccharides and DNA dissolve in water making it the basis of life.

Every planetary system has an “habitable zone” where a planet can maintain liquid water on its surface. Earth is within this zone as well as Venus and Mars, but these three planets are very different from each other! This leads us to one of the most important conditions for life: a life-friendly atmosphere. Venus has an extremely dense atmosphere which consists mainly of carbon dioxide, thus the pressure at the planet’s surface is about 92 times that at Earth’s surface and it generates (along with other greenhouse gases) a strong greenhouse effect, creating surface temperatures above 450 ºC. In the other hand, Mars has a thin atmosphere and no greenhouse effect turning the planet in a big cold desert. Because Mars’ mass is only 10% the mass of the Earth, it makes atmosphere retention difficult and the constituent molecules are more likely to be lost to space when buffeted by solar wind. Here on Earth, the atmosphere has just the right amount of CO2, keeping the temperature suitable for life.

Earth’s magnetic field protects us from solar wind and cosmic radiation which damages our cells. It is caused by electric currents in the liquid outer core which combined with the planet’s rotation creates a dynamo responsible for the magnetic field.

Now we know that atmosphere, mass, a liquid outer core and a right amount of planetary rotation are also major conditions for maintaining life.

However, there are organisms capable of living under extreme conditions such as high/cold temperatures, high levels of radiation, high salinity, acidity, etc… These organism are called ‘extremophiles’. This is amazing because it tells us that life can thrive even in planets with harsh conditions and perhaps life is not so rare in the Universe as we may think at first glance.

Most extremophiles are microbes like bacteria and archaens (primitive bacteria-like organisms) and are thought to be the first organisms on Earth and they are the most likely to survive to an extinction caused by a catastrophic event.

Astrobiologists are very interested in extremophiles, as many organisms of this kind are capable of surviving in environments similar to those known to exist on other planets or moons of our Solar System. Some people speculate that Mars may have regions that could harbor communities of extremophiles as well as in the hypothetical subsurface ocean of Europa (a Jupiter’s moon). Titan, Saturn’s largest moon (and the second-largest moon in the Solar System), has a dense atmosphere mainly constituted of nitrogen and trace amounts of methane and other hydrocarbons. Cassini spacecraft and the Huygens probe found evidence of lakes of liquid methane as well as clouds and even rain! There has been some speculation that methane may have a role similar to the importance of water here on Earth and maybe some bacteria could live on Titan’s surface.

Some people believes that life exists throughout the Universe, in asteroids or other small space junk, in a dormant state until it encounters a suitable environment. This is know as the “Panspermia hypothesis”. Panspermia proposes that forms of life like extremophiles become trapped in debris that was ejected into space after a collision between a planet which harbor life and comets or asteroids. This kind of organisms may travel dormant for an extended amount of time before colliding with other planets. If the new planet has suitable conditions, the bacteria becomes active and the process of evolution begins. Of course, the bacteria would have to resist to high pressures, high temperatures, radiation, etc. The mechanisms proposed for panspermia are hypothetical and currently unproven and most scientists remain skeptical about this.

But the hundred million dollar question is: extraterrestrial life exists? Life could have emerged in other planets? The truth is that we never found alien life or even evidence of it, neither in the Solar System nor in exoplanets. But this means that we are alone in the vast Universe? Our little planet is that special and unique for life and there isn’t another planet capable of support life in the big dark ocean out there? I don’t think so.

Why? Well, our galaxy has thousands of millions of stars and there are thousands of millions of galaxies throughout the Universe, so the total number of stars in the cosmos is unimaginable! With the discovery of exoplanets, it is not hard to image that many of those stars have planetary systems which can have planets capable of harbor life. In fact, it would be improbable for life not to exist somewhere in the Universe due to the astronomical numbers of galaxies, stars, planets and moons.

With that in mind, Frank Drake formulated his equation in 1961 as a way to focus on the factors which determine how many intelligent civilizations may exist in our galaxy. Drake’s equation depends on factors such as: the total number of stars in the Milky Way, it depends on the fraction of those stars that have planets, it depends on the average number of planets that can potentially support life per star that has planets, it depends on the fraction of those planets that actually go on to develop life at some point, it depends on the fraction of inhabited planets on which intelligent life emerges, it depends on the fraction of those worlds where intelligent beings evolve to be able to communicate and finally, it depends on the fraction of a planet’s lifetime that is graced with a technological civilization.

I strongly advise you to see episode 12 “The Encyclopaedia Galactica” of the famous TV series “Cosmos” presented and written by Carl Sagan. In that episode, Carl Sagan obtained from Drake’s equation that there are 10 civilizations capable of communicate in the Milky Way.

Of course, no one knows those parameters exactly and they give us only a hint of the number of technological civilizations in our galaxy. But remember that the Universe has lots of galaxies! So, even if the outcome of Drake’s equation is a very small number, that number multiplied by the estimated number of galaxies in the observable Universe will probably yield a considerable number of advanced civilizations in the whole cosmos! And the number of non-intelligent life has to be even greater!

We saw that life is possible outside planet Earth, but how we will find it? The distances are so great that we can’t send spacecrafts or probes to other worlds. But we can try to listen.

There are projects, like SETI, that use radio-telescopes to survey the stars, looking for radio-signals or messages from another intelligent beings. Now, you may be wondering how we will understand their messages, because no one expects that they can speak English or any other human language. But there is a universal language: mathematics. They can send a signal with a series of prime numbers, or the Fibonacci sequence, or something else that any intelligent civilization will understand as a message, clearly distinct of any other natural radio source.

I hope you enjoyed this podcast. Thanks for listening and you can now wonder beyond the horizon, beyond planet Earth.

M13 and Phoenix Astronomical Society

Phoenix Astronomical Society has a great newsletter with many useful information and different topics; in this month's newsletter they have an image of M13 taken by me (dated from last August) published there; the image is on page 4, as well as some very interesting information about this messier object.

I recommend you to look at other issues and to keep an eye on those interesting newsletters.

AAPOD - 09/04/10

É com agrado que vejo mais uma foto minha como AAPOD!
Link permanente:
http://astronomy.fm/aapod/2010-04-09/images/aapod/2010-03-29-1269888915.gif
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Today's AAPOD is my shot of Sunspots 1057 and 1059!
Permanet link:
http://astronomy.fm/aapod/2010-04-09/images/aapod/2010-03-29-1269888915.gif

Sunspots - 28/03/2010

Aqui fica uma foto do Sol tirada hoje com o meu Solarscope e Canon 1000D. São visíveis as manchas solares 1057 e 1059 (próxima do limbo). A imagem está invertida horizontalmente e também na vertical, devido ao sistema lente-espelho do Solarscope. A imagem original é com luz branca projectada pelo Solarscope, mas para dar um ar mais "quente e côr mais habitual" à foto diminuí o canal azul e verde e aumentei ligeiramente o vermelho (com o Gimp). Há já bastante tempo que não via as manchas solares visto que o Sol tem andado calmo, mas já se nota um aumento significativo de actividade solar.
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Today, the Sun looked like this. I took this photo with my Solarscope and Canon 1000D. The sunspots 1057 and 1059 (near the limb) stand out quite nicely. The image is horizontally and vertically flipped because of the optical system lens-mirror of the Solarscope. The original image is seen in white light, but I managed (on Gimp) to decrease the blue and green channels and increase the red one a little bit to give this color to the solar disk. The Sun is waking up with activity...

U Scorpii Erupts As Predicted

One year ago, Bradley Schaefer predicted that the recurrent nova U Scorpii was about to explode again. In the morning of January 28th, amateur variable-star observers Barbara Harris and Shawn Dvorak announced that U Sco brightened from magnitude 18.0 to 8.0!!! It can now be seen with an ordinary pair of binoculars.

Source:
http://www.skyandtelescope.com/observing/home/82967237.html

Moon(s)

Moonfruit

Close-up

Moon with Jupiter at top left

Moon in the sky

These moonshots were taken in 19th December of 2009, but I only managed to post them today. Hope you like it.

365 Days of Astronomy Podcast - 4th October

This project will continue in 2010 and I will contribute with another podcast this year. The title is "Life in the Universe: Odds and Expectations"; I'll try to talk about everything about life in the Universe (including Earth) and perhaps open a discussion of ideas after it, here in the blog. This is a subject where imagination and extrapolation play a big role, but we should not forget the scientific facts...

Abstract: This podcast is about the odds of life emerge in our Universe. We will see how extraordinary and improbable is our existence. We will seek for the conditions a planet must have to support life and what are the odds of life arise in such a planet. How would be the contact with other civilizations? Is it possible or it's just fiction? How the extraterrestrials may look like? How we will communicate? In this podcast I will try to answer to this questions and to reach several topics. This questions make all of us wonder, and my intention is to make you wonder beyond the horizon, beyond Earth.

ISS passing close to the Moon

No dia 27 de Setembro vi que a ISS iria passar perto da Lua e lá fui montar o 1000D no tripé. Quanto a ISS apareceu, tirei esta foto. Somente 1º ou 2º separavam os dois intervenientes no ponto mais próximo. Parecia mesmo que ia contra a Lua! Duas fotos foram tiradas para esta composição.

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On the September 27 at twilight I noticed that the ISS would pass close to the Moon, so I putted my Canon 1000D on a tripod and waited. It was wonderful seeing the ISS running towards the Moon! At the closest point the distance between them was only about a degree or two! The image is a composition of two shots.

AAPOD - 18/11/09

http://astronomy.fm/aapod/2009-11-18_Mooncatching.html

1 Minuto de Astronomia - AIA2009

Não percam os "spots" do AIA 2009, a serem transmitidos pela RTP.

http://www.1minutoastronomia.org/

RTP1
Quarta-Feira, 4 de Novembro 9:27 / 11:37 / 17:10 / 18:30
Quinta-Feira, 5 de Novembro 9:21 / 11:36 / 14:20 / 17:08 / 18:40 / 22:47 / 02:38
Sexta-Feira, 6 de Novembro 9:28 / 11:36 / 14:22 / 17:11 / 18:37 / 0:57 / 2:40
Sábado, 7 Novembro 9:49 / 11:35 / 15:58 / 17:15 / 18:13 / 22:59 / 02:55
Domingo, 8 de Novembro 10:00 / 14:45 / 17:12 / 18:28 / 22:59 / 02:41

RTP2
Quinta-Feira, 5 de Novembro 13:00 / 20:31 / 21:06 / 1:15 / 2:07
Sexta-Feira, 6 de Novembro 13:58 / 16:47 / 19:25 / 0:18 / 02:00

Um bom AIA para todos!

Today's AAPOD - 01/11/09

Para começar bem o mês, a minha foto do Double Cluster foi AAPOD! Esta é das minhas fotos preferidas!

Fica aqui o link: http://astronomy.fm/aapod/2009-11-01/Perseus+Double+Cluster.html

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This month I star off on the right foot, my latest picture, the Double Cluster is the today's AAPOD! It is one of my favourite shots!

Here is the link: http://astronomy.fm/aapod/2009-11-01/Perseus+Double+Cluster.html

Perseus Double Cluster

(click on the photo for full size view)

O duplo enxame do Perseu é um dos mais espetaculares objectos no céu nocturno. No dia 27 de Setembro resolvi fotografá-lo. Com binóculos já faz maravilhas aos olhos e no meu telescópio ocupa todo o campo da minha ocular de 25mm. É maioritariamente constituído por estrelas de cor azulada e tem umas quantas cor-de-laranja que fazem um contraste espetacular. Foi uma foto rapinha, apenas um total de 6 min de integração, 2o darks; um objecto a revisitar seguramente.

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The double cluster in Perseus is one of my favourite objects in the night sky. It is an easy binocular target, but through a telescope the view is amazing. In my 8 inch f/5 reflector it fills all the FOV of my 25mm eyepiece. I love the contrast between the orange and whitish-blue of the stars. This one was a quicky, with just 6 min of total exposure, 20 darks; I'll definitely revisit this one!