Hubble and Another Moon!

Mark Showalter of the SETI Institute in Mountain View, California has discovered 14th known moon of planet Neptune using Hubble Space Telescope's data of Neptune obtained in 2009!  This moon is 12 miles in diameter, the smallest and the faintest of the Neptune moons.  It is so faint that even escaped detection by Voyager 2 Spacecraft in 1989 that flew by Neptune to survey this planet.  Showalter detected this moon on July 1, when it was 65400 miles away from Neptune!  This moon is currently referred to as S/2004 N 1, and orbits the planet, based on Showalter calculations, once every 23 hours!

Yet another reminder that we are just beginning to know our own backyard, the solar system, and that Hubble remains one of the major innovations of the last century with high, if not the highest scientific impact, among other innovations.  To learn about Hubble discoveries to date, please visit here. 

"This composite Hubble Space Telescope picture shows the location of a newly discovered moon, designated S/2004 N 1, orbiting Neptune. The black and white image was taken in 2009 with Hubble’s Wide Field Camera 3 in visible light. Hubble took the color inset of Neptune on August 2009. Image Credit: NASA, ESA, M. Showalter/SETI Institute"

To learn more about newly discovered Moon of Neptune, please visit here.

Reference:

[1] http://www.nasa.gov/content/nasa-hubble-finds-new-neptune-moon/#.UelHpRaUdjC
[2] http://hubblesite.org/hubble_discoveries/

QE2s

As most of you know the name of the asteroid 1998 QE2 reminds many of the cruise ship QE2.  This nice video tells you how the properties of the QE2 of the skies relates to those of the seas:




Reference:
http://www.youtube.com/watch?feature=player_embedded&v=Gp8576W8QHU#!

1998 QE2

During the past weeks we have heard about asteroid 1998 QE2 and how it has got closer than any other asteroid to Earth.  Whether or not it poses any dangers to us or not (well, it does not). In fact, the closest approach of this asteroid to Earth occurs tomorrow, May 31, 4:59 pm Eastern Time, "when the asteroid will get no closer than about 3.6 million miles (5.8 million kilometers), or about 15 times the distance between Earth and the moon". As eyes were on this asteroid to capture this approach, NASA scientists discovered that QE2 has its own moon!   Radar data of NASA's Goldstone Deep Space antenna in California were used for this finding.  Images were taken from "3.75 million miles (6 million kilometers) from Earth, which is 15.6 lunar distances." To learn more read here.

Yet, I wonder, where is my moon?  I mean Vesta's moon?

Reference:

http://www.nasa.gov/mission_pages/asteroids/news/asteroid20130530.html

Hubble Does it Again, Time After Time!

There are at least three major science news releases thanks to data of the Hubble Space Telescope. Hubble is not giving up on the Jaw Dropping business!

1) "When astronomers detected intense radiation pumping out of the Crab Nebula, one of the most studied objects in space, at higher energies than anyone thought possible, they were nothing short of stunned." Learn more here.

2) "Observations made by NASA's Hubble Space Telescope of a special type of supernovae contributed to research on the expansion of the universe that today was honored with the 2011 Nobel Prize in Physics." Adam Reiss, an astronomer at the Space Telescope Science Institute, Krieger-Eisenhower professor in physics and astronomy at The Johns Hopkins University in Baltimore, Saul Perlmutter, an astrophysicist at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory won the Physics 2011 Nobel Award for transforming our understanding of our universe by discovering that not only the universe is expanding, but also its expansion is accelerating. Learn more here.

3] In a re-analysis of 1998 Hubble data, astronomers have found "visual evidence for two extrasolar planets that went undetected back then."

Just static?

Do you remember the static on analogue TVs?  If you live in the U.S. the analogue signals are not broadcast anymore, and what it means is that our old friend, the TV static, is gone.  Well, why should we care you ask?  Just for childhood memories?  What were you calling those when you were a kid? Did you compare them with snow flakes like most kids do?  Well, I for one have a good memory of my brother pulling my leg about it once.

One day after school he ran to my room, excited and happy.  "Have you heard about the new cartoon?", he asked.  "No, what cartoon?".  Now, let's get some perspective,as it is always good.  At that time we were living in Iran.  It was during war years.  We had only two public channels, each having programs for children one hour a day only.  Not all their cartoons were brand new either.  Some we had watched several times.  Anyways,  he told me how it was a foreign made brand new cartoon, maybe European or American.  It was fictional too!  It was about colony of aunts trying to survive a hard winter.  It always snowed where they lived, and yet ants, the hardworking organized creatures they are, they always survived.  It was about their stories and struggles, and if it was not exciting enough, that show was on all the time whenever there was no other program.  That was like a dream show!  You can imagine my face when we turned on the TV after running downstairs impatiently for me to see this brand new cartoon.  That was my most exciting experience with TV static.

Now, I have learned it was something even more exciting!  Not just because of our imagination and story telling talents in absence of enough entertainment, but for our own amazing universe and how it was born.  Did you know that every time you watch static on TV, you are also observing parts of the Big Bang?  The microwave radiations it had sent us billions of years ago, which have just reached us?  Is not that amazing?  Do not you miss watching Big Bang on your own TV?

http://www.youtube.com/watch?v=DjLtdorH0iE

The child in me is happy to get back at my brother with a better story.

Redshifts

Astronomers often calculate what is called redshift to determine different properties of celestial bodies, mainly their distance from us.  The redshift is often related to the Doppler effect of the light that is coming to us from that body, say a star.  In the same way that an ambulance siren's pitch varies to our ears when it approaches and leaves us,  the light spectrum of a star varies to our eyes (telescopes) as it travels through the space.  The change in wavelength of  that body's spectrum determines its redshift.

So far so good.  We have a simple and yet powerful concept to work with.  We can effectively derive the age, distance, velocity, temperature, and mass of bodies billions of miles away from us just by looking at their light spectrum's period and amplitude.  You see redshift and Doppler effect in so many astronomy papers and textbooks that even to a non-astronomer like me they become common knowledge. Something as famous and powerful as E = mc^2 or F = ma.  And just as you feel a little comfortable and confident about calculating at least one thing in astronomy, here came our professor and announced the biggest misconception in astronomy textbooks:  The redshift of galaxies is not due to Doppler effect, it is due to the expansion of the universe! Astronomers call this cosmological redshift!  Doppler effect is responsible for redshifts in our solar system and in our own galaxy.  When we look at spectra of other galaxies, their redshift is a result of the Hubble's law!

Ouch!  My summer intern was calculating redshifts for galaxies and he had mentioned Doppler effect in his report.  I emailed him directly from the training.  They cannot get a return on investment from an Astronomy for Engineers training any faster than that!  Of course, it does not affect calculations of the redshift and the results, but just the motivation behind the solution was not stated correctly scientifically.

Neutron Stars

Neutron stars are leftovers from huge beautiful explosions called Supernova.  They are the destiny of the dying stars if their core mass ends up less than three Sun masses.  They are very dense.  What is their density?  10^12  g/cm^3.  Think about that for a minute. More fascinating is that they rotate very rapidly.  Can you imagine how fast they rotate?

Let's get some perspective.  The Earth goes around itself once every 24 hours.  Our Sun,  the size of a million Earths,  rotates around itself once in about 25 days.  These dense stars, Neutron stars,  on average have a mass equivalent to 1.5 Sun masses.  How fast do you think they rotate?  Like Sun? Maybe twice faster? or maybe 25 times faster, going around themselves in 1 day or so?  Are you ready?

Neutron stars have a period of 0.0003 to 4 seconds.  That is every 4 seconds they can rotate somewhere between  once to 12000 times, while being as big or larger than our Sun!  Can you imagine something that huge spin that fast?  60 times to 720,000 times a minute?  Can you imagine if our Earth rotated that fast?  If you cannot be amazed and fascinated by this, like our professor said today, I give up!  I leave and never write or teach anything else.  That is it!

Yet, these massive and rapidly rotating bodies have properties with frequencies more accurate than the best atomic clocks we humans have built to date.  They are universe's most accurate clocks.  I get to that property some other time.

The Skies

I am taking an astronomy class these days from 8am to 5pm!  I have learned enough today that I can write about them for at least a month on a daily basis.  However, now I am too tired to write about the more sophisticated lessons and historical stories of astronomy.  I just go over some interesting trivia!

The class started on a sad note:  that humans 40,000 years ago were much more familiar with the skies than we are.  Most people used the sky at least as their clock, map, and calendar. You could ask any random person to show you a particular star or constellation  on a dark sky, and that person could quickly do that.  It is hard to imagine a random person these days passes this test.  I myself cannot locate famous stars and planets naturally.  Can you?  I should work on that.

So, here are the trivia:

1) "Moon" is from the Greek word Metron meaning to measure!  As it was mainly used to measure different things in old times.
2) "Clock" is a German word meaning Bell, since traditional clocks were made of bells.  Remember these?
, and finally
3) Brahe was a Danish astronomer who became the first federally funded researcher.  He has funny stories.  Maybe  I tell you sometime.

Till then,
Good night!

Yet another Moon!

Today's lesson of the day is a no-brainer! Pluto's fourth moon is discovered!

Pluto is becoming more and more interesting! It was only in 1930 that Pluto itself was discovered! I let you entertain yourself to the story of what led to that discovery! The first and biggest moon of Pluto, Charon, was discovered in 1978 by astronomer James Christy.

For decades we grew up thinking of Pluto as a planet in our solar system, a planet with a big moon, just like our home planet! Until 2005, when two new moons of Pluto, Nix and Hydra, were discovered, and later verified with 2006 HST observations. This discovery made Pluto lose its planet status and be classified as a dwarf planet! I let you hear about this discovery's story from the person who made it, Max Mutchler!

Just as textbooks were changed and teachers and the general public were adjusting to Pluto not being a planet and having three moons, here comes today's discovery! Ironically during a time when many eyes are on Vesta and working hard to find a moon of it! Pluto comes and steals the show :-) New Horizon mission will have a lot to visit and learn about during its Pluto fly-by in 2015!

Now I wonder if this 4th moon appeared in 2005/2006 HST Pluto images and was undetected/missed or that it was somewhere else in its orbit and not in those frames. If it was missed before, we, especially the Dawn team, have to learn how and why it happened before it is too late.

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p.s. Can you imagine how exciting 2015 will be? We see Pluto and its moons from New Horizon's eyes, and we see Ceres and all it has to offer via Dawn mission! We are going to see so many new worlds for the first time, and soon later in 2016 Juno reveals Jupiter to us!