Almost one month ago, everyone was in comet hunting mood. Me too.
In Malaysia, this Comet PanSTARRS was not more than 15 degrees above the horizon. To us, it was a challenge, because we seldom have a clear cloudless horizon. But unwilling to give up easily, I spent every evening for one whole week at different locations staring at the western horizon, hoping to get a glimpse of the comet.
But without any luck…
But not all is lost, while waiting for the comet to appear, the cameras were happily snapping away and below is the result. Enjoy.
Last November (2012), I went to Nan, Northern Thailand to attend a family function. Nan is a small town with minimal light pollution, and is a fantastic place for stargazing. I spent two nights on the rooftop balcony catching the star lights.
I bought along with me two cameras, Canon EOS350D and 60D, Vixen Polarie Star Tracker plus a tripod and two ball heads. Since I need to travel around, I had to minimise my stuffs. This setup provided me with all I need to capture the stars, and at the same time, did not weigh me down, especially when I can replaced my bulky equatorial mount with a camera-body-sized Polarie star tracker.
During my two nights in Nan, and later one night in the nearby Doiphukha National Park, I dedicated one camera for shooting timelapse, and the other for still images. I used Polarie for two purposes: as tracking system, and for panning effect in timelapse.
The setup of Polarie was simple and fast. It took me less than 10 minutes to hook up everything onto the tripod. As I was in Northern Thailand (~19 deg N), Polaris was easily visible. I pointed the small hole (on the top right corner) to the star Polaris for polar alignment. When I looked through the hole, the field of view is relatively large compared to the star. Sometimes I was not quite sure if Polaris is exactly at the centre or not. For those who are not familiar using a telescope’s finderscope to search for stars may have difficulty trying to determine whether the star they are seeing through the hole is Polaris or not. But to me it was OK since I’m a seasoned telescope user.
First, I shot a wide-field view (FL17 mm) of Jupiter together with Taurus, Auriga and Perseus with exposure times of 1 min and 4 min. The tracking was good with slight but not obvious trailing of stars.
FL17 mm, 1 min (click to enlarge)
FL17 mm, 4 min (click to enlarge)
Next, I framed Orion with a higher zoom (FL50 mm). For a 3-minute exposure shot, the tracking was good with the stars showing some nice round dots. Signs of trailing started to show up in a 4-minute shot and became evident when exposure time is longer than 4 minutes. The reason may be due to the polar alignment inaccuracy as mentioned above, which will become noticeable as the focal length or exposure time getting longer. To solve this problem, Vixen has two optional accessories: the Quick Polaris Locator Compass and Polarie Polar Axis Scope. The Compass can also be beneficial when Polaris cannot be seen, for example if a tall building or trees is blocking the view of the north.
Orion, FL50 mm, 3 min (click to enlarge)
Orion, FL50 mm, 4 min (click to enlarge)
Orion, FL50 mm, 5 min (click to enlarge)
Polarie was also used as a panning device for my timelapse movie, and I just love the results. There are two scenes in the video below that showing the panning results by using Polarie. The first one is from 0:39 to 0:47, I was halfway through the scene when the clouds rolled in and forced me to terminate the sequence. The second one is from 1:52 to 2:31, taken in the National Park where the surrounding was full of trees. The stars were only visible on a small patch of sky above and between the some trees. Then I got this idea of moving my camera along the gap between the trees to capture the stars, and the result was, well, you can see for yourself in the video.
Stars of Northern Thailand
The Setup: one camera was mounted on Polarie and the other camera was mounted directly on the tripod. This setup was for shooting timelapse.
Lastly, I would like to talk about the battery consumption. Polarie uses either two AA batteries or an external power supply (such as a power bank through a mini USB port) as its power source. In my case, I used rechargeable AA batteries, and averagely it can last for 2 hours. I would like to note that I’m using old rechargeable batteries where their performance had already deteriorated. For new fresh batteries, it should be able last longer.
Overall, I’m very happy to have Polarie when I was out shooting. Its compactness makes my travel lighter and its ease of use makes my shooting session more efficient. I’m looking forward for my next night to use it again.
They call 2013 the Year of the Comets. When you can have 3 naked eyes comets gracing the sky in a year, 2013 definitely deserves the title.
Comet PANSTARRS (C/2011 L4)
The first one is called Comet PANSTARRS. PANSTARRS, stands for Panoramic Survey Telescope & Rapid Response System, is the telescope that discovered the comet. This 1.8-m telescope is located atop the Haleakala volcano in Hawaii. This comet already put on a great show in the southern hemisphere, and now our fellow Malaysians also had captured the comet in Negeri Sembilan and Sawarak.
It was estimated that the comet is the brightest between March 8 – 12, with roughly the magnitude of zero. But bear in mind that a comet’s magnitude is the estimate of the light emitted by the whole (extended) object, while a star is a point of light. Thus, when Comet PANSTARRS reaches a magnitude of zero, it won’t appear as bright as a zero magnitude star because the comet’s light will spread out over a larger area.
The video below shows the position of the comet for Kuala Lumpur, Malaysia from 8 to 30 March. The chart was produced using Stellarium. If you do not have Stellarium, go and download one now! It’s an open source planetarium software that can show you how the sky looks like anywhere on Earth. And since Comet PANSTARRS is the hot topic now, you wouldn’t want to miss it. So, once you have installed Stellarium, follow this video to add Comet PANSTARRS (and other comets). Now you can know when and where the comet is visible at your location.
To observe the comet, you need a clear and unobstructed western horizon, it only visible for 1 hour after sunset. Be early at the observing site, you can enjoy the beautiful sunset while searching for the comet. If the sky is clear, we should be able to see it with the naked eyes, if you have binoculars would be better.
Comet Lemmon (C/2012 F6)
The second one is called Comet Lemmon. The comet was discovered by A. R. Gibbs using the telescope at the Mount Lemmon Survey, located in Catalina Mountains north of Tucson, Arizona, USA.
Comet Lemmon is actually located quite near to Comet PANSTARRS, but the sighting favours those in the southern hemisphere. If you are lucky to have a clear sky, you can capture both the comets in one picture, as shown in the beautiful picture below. You can also notice the different colours of the comets: Comet PANSTARRS (near the horizon) is showing its dust tail reflected by sunlight, whereas Comet Lemmon is sporting a green tail dominated by glowing ions.
Credit: Yuri Beletsky (ESO)
The charts below show the positions of Comet Lemmon and Comet PANSTARRS for Mar 10 and 15 in Kuala Lumpur, Malaysia (use the same method as above to add Comet Lemmon into Stellarium). For us at the equator, Comet Lemmon lies near to the horizon and poses a challenge to spot it. Hopefully, we also can capture a picture of dual comets like the one above.
Comet ISON (C/2012 S1)
The final comet is Comet ISON, which hopefully will put on a great show in November. At its brightest, it is predicted to be brighter than the full moon! We will just have to wait and see. I’ll write more on it when the time is near.
So, for this whole week, do not do overtime, go out before sunset and try to catch some comets!
Clear skies and Happy Comet Hunting!
This is a picture I took last month in Northern Thailand.
It was a sky full of stars, with the Milky Way band at the bottom. If you pay some attention, you can see an elongated fuzzy blob right of centre, among the trees (click for bigger version). And if you familiar with the sky, you will know that is Andromeda Galaxy.
Andromeda Galaxy or M31 is about 2.4 million light-year from us – our neighbour in cosmic scale. It is the closest big spiral galaxy like our own Milky Way and is easily visible to the naked eyes on a clear night. Now, imagine how this big and near naked eye galaxy will look like using the Hubble Space Telescope (HST).
Individual star clusters in the galaxy can be seen.
And you can help to find them.
Join the newly launched Andromeda Project.
This project is asking anyone who is interested to help examine thousands of HST images of Andromeda Galaxy and identify its star clusters. Star clusters are groups of hundreds to millions of stars that formed from gas at the same time so all the stars have the same age. Star clusters are important because it hold clues to the evolution of galaxies. We are all curious how galaxies like our own Milky Way form, and Andromeda is the best place to study that process since our position within our galaxy makes it hard to study our history.
So far, scientists had looked through part of HST images and just manage to find 600 star clusters. It is believe that the full set of images contains 2500 star clusters. It is too time-consuming for a few scientists to look through such a big set of data, and the pattern-recognition software is not really that helpful.
So, instead of drowning the scientists with all these data, public were asked to help explore this galaxy next door. Registration is not required and a simple online tutorial teaches you how to recognise and mark the star clusters. Just go to the website – Andromeda Project – and get started.
I strongly agree with Cliff Johnson, a University of Washington graduate student working on the project: “You don’t need to know anything about astronomy to participate, and it’s actually pretty fun, like playing an online game”.
So, if you are free, why not spend some time doing some real science?
Eight months ago, NASA launched Curiosity (Mars Science Laboratory, MSL) on a 560 million km journey to Mars, and in less than 2 days’ time, Curiosity will touchdown on Mars, on August 6, 1:31 pm Malaysia Time (5:31 am UTC). This 950-kg rover is beyond anything we ever sent to another world – it is the heaviest laboratory and the suite of mechanical systems and scientific instruments are the most sophisticated we ever put on the Red Planet. Its primary science goal is to explore Mars as a potential habitat for life, either past or present.
If you wish to follow the landing live, you can watch NASA TV, or join a group of astronomers and enthusiasts at Google+ Hangout. You can find more info at Universe Today or their Facebook events page.
Before Curiosity can explore Mars, she will have to land safely. And since she is too heavy to use airbag, as the previous rovers did, engineers had to design a unique landing system to deliver her safely on the ground. It includes a sequence of steps that we could not control or even witness in real time because signals take 14 min to reach Earth from Mars. All will be done by the onboard computer. This 7-minute of terror from Mars atmospheric entry to touchdown include a heat shield, a huge parachute, retro-rockets and a sky crane to slow her from over 13,000 MPH to 0 MPH. Hundreds of things have to go just right.
Profile of entry, descent and landing events, for one typical case. Exact timing will be determined by atmospheric conditions on landing day. Credit: NASA
The two videos below by JPL nicely summarised the whole process (make sure you watch both of them!).
Curiosity will land on the floor of Gale Crater, 5 degrees south of the Martian equator. Gale Crater is an ancient asteroid impact about 154 km wide. Gale Crater is a fascinating place to explore because of the mountain of layered materials in the middle. Studies from orbit have revealed that the layers have different minerals depending on their height. These different layers represent different environmental histories of Mars. The layers tell a story about what Mars was like in the past, perhaps spanning much of the early history of the Red Planet.
Curiosity carries a variety of science payloads to conduct a comprehensive search for signs of life, which includes remote sensing, contact instruments, analytical laboratory and environmental characterisation.
The two interesting videos below show the locations of the science instruments and how do they work:
- NASA Curiosity Homepage
- Curiosity Fact Sheet (NASA)
- Curiosity Landing Press Kit (NASA)
- Strange but True: Curiosity’s Sky Crane (Science at NASA)
- Quick and Curious Facts about the Mars Science Laboratory Mission (Universe Today)
- Chemistry on Mars: The Curiosity Rover’s Mission (Youtube)
- Wheaton Guides Curiosity’s Fans to Red Planet (Youtube)
Last Friday (Jul 13), our university (UTAR) hosted a talk by the first Japanese astronaut, Dr Mamoru Mohri. A veteran of two space flights, Dr. Mohri has logged over 459 hours in space. He flew aboard Space Shuttle Endeavour as a payload specialist on STS-47 in 1992, and as a mission specialist on STS-99 in 2000.
The talk lasted slightly over an hour, it was very interesting and I learned a thing or two.
He started the talk by telling how he got interested to become an astronaut. He was inspired by Yuri Gagarin, the first human in space, that he asked his brother to take a picture of him with Gagarin in the television. In 1963, a total solar eclipse swept through his hometown, strengthen his interest in space. However, he had to put his dream as an astronaut aside because during that time only a Russian or an American can be an astronaut, and he was none of both. His dream became a reality when, at the age of 35 (if I remember that correctly), Japan was seeking for candidates to be an astronaut. He succeeded to become the 7 finalists sent to NASA for training.
He then showed us some videos of Earth taking from space, telling us his experiences how the Earth look like through his naked eyes. It was not the same as what they looked like in pictures.
He also showed the videos of him running experiments in space: blowing bubbles in water sphere, examining the properties of water (surface tension and wettability), colliding water sphere with metal sphere. The most interesting part of the talk is that before he showed us the outcome of the experiments, he’ll walk around and asked the audiences what result they expected, forcing everyone’s brain into high gear.
One of the most simple and yet very interesting experiment was investigating how our body changes in space. On the ground, Dr Mohri measured the size of his neck and thigh. So when he was in space, what do you think will happen to the size of the neck and thigh? Getting bigger or smaller? Frankly speaking, I didn’t get the right answer. My first instinct was it should get bigger, since in space the pressure is lower. However, I also know that the cabin will be pressurised to atmospheric pressure, if not, how were the astronauts going to live there? So my answer was there should be no changes, but my guts told me that it was not right.
So it turned out that my guts were right, there were some changes. The neck will get bigger while the thigh will get smaller. Why? Because our body is mainly made up of fluids. On Earth, gravity pulls the fluids to the lower part of the body, making the neck smaller and thigh bigger; in space, since there is no preferred direction, the fluids in our body will distribute evenly. Thus, in space, the neck will be slightly bigger and the thigh will be smaller.
(I tried to search these videos online to post them here, but unsuccessful… sorry…)
He wrapped up his talk by, again, taking us around the Earth as viewed from space, and finally Earthrise from the Moon taken by a Japanese spacecraft, Kaguya.
All in all, it was a great talk, and I think everyone enjoy themselves a lot.
Lastly, I can’t help not to mention that I was honoured to be the emcee of the event, introducing Dr Mohri to the audience and reading his biodata. This is not something that you are given the opportunity to do every day!
All photos courtesy of Lee Choon Kuan.