Get ready sky watchers, the Perseids are coming! The bright and mighty meteor showers, known as the Perseids, are all set to light up the night sky with their flickers of bright light. The name comes from the constellation they seem to originate from – Perseus.
The Peak of the Shower: Timing
The peak of the shower falls on the nights of 11/12th of August (tomorrow night). The peak, being a slightly broad one, will also cross into the 13th. The showers will last till the 24th of the month, but if you miss the peak, there is no point in hunting out the faint trails later on. Simple advice: Don’t miss it tomorrow!
The showers will be visible through the night. You might want to catch up with them late evening and spend your time with them till night falls. The late moonrise will help ramp up the grandeur of the spectacle.
The moon rises at about 1:30 AM on these two days and by the time the moon reaches anywhere near the zenith, it will be nearly predawn and you’d already be feeling sleepy. The moonrise on the 13th of the month happens at about 2:30 AM and, by that time, the peak of the shower will already have passed. Moreover, the bright planet, Venus and Jupiter, will be close to the moon, so they won’t spoil your view either.
The Origin of the Perseids
The Perseids happen because of the comet Swift-Tuttle. Meteor showers happen when the Earth passes through a path of debris left behind by a comet which has just passed through that region. The debris then fall through the Earth’s atmosphere, burning up in the process and creating the brilliant flickers that we see.
Now, of course, as the years go by, the intensity decreases, because the comet’s orbital period around the sun is way longer than the Earth’s. The next time Swift-Tuttle visits out neck of the woods, it will be in the year 2126. Don’t try to hold your breath that long.
Location Location Location
Choose a location away from the city, if you can. The lesser the light around you and the lesser the fog/smoke in the surrounding atmosphere, the better it is. Of course, all of this means that the nights will get really chilly. Make sure you have a proper blanket, coat and mattress. Spraining your neck is not such a great idea, and thus, reclining against a soft is definitely a good idea.
The shutterbugs will definitely want to get their shots and it will be a good idea to go for long-exposure shots. Patience to make multiple attempts is the key; photo contrast is king!
You’ve just seen a few, but you have not seen them all! Curiosity is running at its peak sending back images by the dozens!
Starting from an egoistic shot of its own shadow, Curiosity has gotten down to business and is busy clicking the rugged Martian landscape. Its NAVCAM (NAVigation CAMera) mast has now been raised and it is taking photos with the camera placed there as well.
Here is a small gallery of the images that Curiosity has shot with detailed explanations.
The two photos shows Curiosity’s shadow on the surface of Mars, the left one before the dust has been removed and the right one after dust removal. The mountain in the background is Mount Sharp, the ultimate destination of the Mars Rover.
Note that this isn’t the high resolution image. That’s coming up in a bit.
Landscape portrait in context
This is an interesting image. The colour film, made slightly transparent to put it into the perspective of the landscape, is the actual photo taken by Curiosity’s Mars Hand Lens Imager(MAHLI). During descent, this got covered by a thin film of dust and thus this isn’t the best available photo.
The background has been simulated with the help of High Resolution Imaging Science Experiment (HiRISE)’s images sent earlier. It also incorporates the images sent in by the Mars Reconnaissance Orbiter (MRO) and those obtained from the Mars Express.
Curiosity landing site
This image was taken by the Mars Reconnaissance Orbiter. It simply shows the different parts of the original Curiosity payload, scattered in different parts across the Martian surface.
These are hopefully the first in a long list of images that NASA will obtain. Curiosity also promises to send in colour panorama photos in a day or two!
More than mere images, we hope that the geological profile of the rocks on Mars will be a revelation.
This is one invasion that everyone is delighted about! Man invaded Mars again, with the giant Mars Science Laboratory, Curiosity, the new Mars Rover, landing on Mars today. The whole payload managed to touchdown on the Red Planet, maneuvering itself with utmost perfection. Remember, all of this happened when Earth was blind to whatever was happening on Mars!
Touchdown and cheers
Things worked out like clockwork. The projected times all matched the real times to a few seconds! If you were watching the live stream from the NASA/JPL control room, you’d know the atmosphere in the room as each stage of the rover was accomplished.
There was a loud cheer when the parachute was deployed, a louder one when the back heat shield separated from the main body and the loudest was reserved for when the rover touched down and the magic words ‘Touchdown confirmed’ were spoken out. The almost childish celebrations that ensued involved people hugging each other, clapping frantically and many breaking down in tears. The scene was one of the most emotional ones you’ll ever see – a perfect antidote to the misrepresentation of science and scientists as emotionless entities.
Images and cheers
The next loud cheer occurred when the Odyssey spacecraft took a grainy 64×64 pixel image, just 4 KB in size, showing one of the wheels of Curiosity on the Martian surface. Odyssey soon sent a higher resolution picture, 256×256 pixel wide. The next image was that of the shadow of Curiosity on the surface of Mars. Never have such tiny images generated so much cheer – and tears!
Here is a video of the control room, showing that dramatic scenes.
The publicized $9 billion papers on the Higgs Boson are out! Both the CMS and the ATLAS collaboration at the LHC, CERN have been working against the clock for the last two months to churn out the result that the world was looking forward to – finding the Higgs Boson. Having found the Higgs Boson and announcing it on the 4th of July at Geneva, the CMS and ATLAS collaborations have now released two papers, both reporting that they have improved upon their earlier presented results.
Stating the Obvious
The 4th July conference had already stated that both the CMS and the ATLAS detectors at LHC have found the Higgs Boson, the long sought after particle responsible for endowing all massive particles with mass. The search has been on since the LHC started running more than two years ago. The long time required just goes to show the magnitude of the search – finding the Higgs Boson wasn’t easy. But make no mistake – the Higgs Boson is definitely there!
Now, these two papers, one by CMS and the other by ATLAS, do something on expected lines – they bump up the significance of the result. This simply means that they make the result more concrete.
Improving the Results
To put in the numbers, the CMS collaboration had quoted a significance of 4.9 sigma or 99.99995% surety of the presence of the Higgs at a mass of 125.3 GeV. They have just bumped up to 5.0 sigma, which means that the surety is not 99.99997% but at a mass of 125.5 GeV. The error bars stay as they are. The decay channels of highest significance are the diphoton (or the gamma-gamma) channel, where the Higgs decaying to two photons, or the ZZ channel, where the Higgs boson decays into two Z-bosons.
The ATLAS collaboration publish a more adventurous result. They have bumped up their significance from the 5.0 sigma announced on 4th July, to the 5.9 sigma! That is a huge improvement, but this also raises a few questions about the analysis of data. How is it that the ATLAS collaboration can bump up their significance so very quickly?
Both collaborations have gracefully dedicated their papers to all those who were associated with the Higgs search, but have passed away and couldn’t see the remarkable results.
All of the questions – and there are many – will be answered in an expected conference in December, when the data collected the LHC in the next three months will be analysed and presented. The LHC is set to go into a period of hibernation after that for about 14 months and expected to resume in 2014.
The new Mars Rover, Curiosity, is poised to land on the Red Planet at 0524 GMT on 6th August. There have been no reported delays or corrections for tomorrow. The final path corrections were made today, and now Curiosity is out there on its own. From the time the Rover, called Mars Science Laboratory or MSL, enters the atmosphere to the time it touches down, the whole world will hold its breath. This is to so-called “seven minutes of terror”.
In this article, I’ll give you everything you need to know about the landing – the time, the place and more. Buckle up!
Landing: The Time!
If everything goes smoothly, Curiosity should touch down at 0731 CET (Central European Time) or 0531 GMT. I will take you through these seven minutes before they happen in this article. The times (all in GMT) given below are all expected times as given by ESA and NASA:
Time: T–6 min, 41 sec; 05:24:34 AM
At an altitude of 125 km, the Curiosity payload sheds two 75-kg tungsten weights. This reduces the weight, but it still can’t fly. Perhaps Allen Chen, JPL’s operations for entry, was paraphrasing Douglas Adams when he said “We’re flying like a brick”. The spacecraft’s internal gyroscopes have to all coordinate to keep the spacecraft aimed at the Gale Crater. The target is barely 20 km across.
Time: T–5 min, 26 sec;
The Earthly package is in free-fall. The atmospheric drag increases the surface temperature to about 21000C. Carbon tiles, specially made to handle such high temperatures, protect the precious load inside. Curiosity is nestled safely inside this package.
Time: T–2 min, 28 sec; 05:28:46 AM
The parachute deploys! It’s nearly 16 meters in diameter! The hearts of all the NASA and ESA engineers are in their mouths. The parachutes are one of the parts most likely to fail, even though that failure possibility is quoted at 1%. This will be a real test for the parachutes, since they have only cushioned drops for much lighter payloads. The altitude from ground is 11km and the payload is still travelling faster than sound at an estimated 425 m/s.
Time: T–2 min, 4 sec; 05:29:07 AM
The heat shield separates! The payload starts sensing the ground approaching. The current altitude is just 8 km and the payload is now moving at 125 – 130 m/s, still too fast to make a proper landing. Crucially, three radar antennas switch on and this is how it knows how far the ground is. The data is useful for the craft to adjust its actions. For the first time, the craft has eyes and its guidance system can kick in.
Time: T– 53 sec; 05:30:40 AM
The back-shell separates. Finally, the world gets a glimpse of the new Rover! The back-shell flies off with the parachute! Curiosity drops down towards the surface, cushioned by the thrust of eight retrorockets. The altitude is less than 2 km from the surface and the craft is moving at a speed of 80 m/s.
Time: T–20 sec; 05:31:17 AM
The sky crane is deployed! This is a complete transformation from previous landings by NASA. So why this sudden transformation? Simple – Curiosity is just too heavy. This calls for a new arrangement – the wheel suspension system can be used as a landing gear. The main craft, Curiosity, then drops down as a thread unspools from the sky crane. The craft gently drops down at a nice pace of 0.75 m/s.
Time: T–0 sec; 05:31:37 AM
Landing: The Place
The site of the touchdown is Gale Crater. The crater is 154 km wide, but the target area is just 20 km. The High Resolution Stereo Camera (HRSC) on the Mars Express spacecraft has just sent back a very interesting picture of the landing area. The image is a false colour image as shown below:
The image suggests the presence of water-based minerals, which might form the basis of life. The lower elevated areas are shown in purple and this forms the target landing area. But don’t miss out on the elevation right in the middle – it’s called Mount Sharp and rises to 5.5 km above the crater floor. Scientists want the rover to land closest to this mountain, as the geologic features there are “very interesting”. The rover will land in the depression, scour around for interesting geologic artifacts and then trudge towards the elevation.
The Eyes and Ears of Curiosity
Meanwhile, the Mars Express will be eyes and ears of the Mars Science Laboratory. The Mars Express Lander Communication (MELACOM) will be switched on at 0205 GMT on 6th August, long before the touchdown.
M-Ex starts recording
Radio signals transmitted by the Mars Rover will be recorded by the Mars Express starting from 05:09 to 05:37 GMT. (For CET times, just add two hours.) This is when the MELACOM receiver switches off and the Mars Express starts off from the dark area of Mars to point at Earth.
M-Ex starts transmitting
The Mars Express starts transmitting recorded signals back to Earth at 06:10 AM (GMT). The data will be transmitted for over 40 minutes with the transmitter shutting down at about 06:42 AM. The only thing left to do for ESA is to transfer the data to NASA.
The Final Words
We’ll be there with you when the massive Mars Rover, weighing in at 900 kg, touches down on the surface. The leaps made have not only been in terms of the technology packed in the machine, but also in the new ways devised to land a very heavy craft precisely on the surface of another planet. The unexpected hurdle came in the form of the black out for the “seven minutes of terror”, during which Curiosity will land, but NASA will be completely blind to it.
So what can go wrong? Charles Bolden, NASA administrator, has a very simple answer – “All sorts of things can go wrong”.
What about all the simulations of worst-case scenarios, rigorous testing of each part and lessons learnt from previous missions? Shouldn’t they be enough? Steven lee, mission’s control systems manager, working in JPL has the perfect closing line:
Probably the overall biggest risk is our lack of imagination.
This channel will have the mission feed, clean and uninterrupted. It will also have the mission audio. Basically you’ll be experiencing what the Curiosity engineers monitoring Curiosity just after landing are experiencing. If that is not cool, I don’t know what is!
Other thank this, you can definitely visit these pages:
An unprecedented day in Indian history has left a lot of questions in its lurch. Arguably the biggest ever power outage in Indian history has taken place today, and at its peak it had left more than half of India powerless. At a time, as many as 19 out of 26 states reported to be without power, but that situation improved quickly. Even then, it wasn’t quick enough to save face and the Indian government has a lot of political questions to answer. We attempt to answer the other question that the public are asking: Why this massive failure?
What happened in India: a summary
It is futile to simply hypothesize the root cause of the trip, but it is clear that over draw of power from the Northern Grid was responsible for the initial failure of the grid. In fact, the Northern Grid had already fallen once yesterday, but was shoddily restored.
Unfortunately, it was drawing too much power from the Eastern Grid while operating at less than full capacity and the Eastern Grid fell too. With two massive power grids out of commission, even large parts of the National Capital were left without electricity. The corridors of power fell dark and, pun intended, powerless!
The official reason for the outage isn’t known. The details might take months to unravel. The truth might be as tangled up as the wires that might have caused this disaster. Instead of foraging for the truth, let us take a look at a couple of other famous power outages, both in North America, and also take a look at what caused them.
Case Study 1: Quebec, 1989
In 1989, a huge solar storm hit North America and specifically knocked out Quebec’s power supply. With Hydro-Quebec out of operation, the load fell on James Bay. With five lines tripping one after the other on James Bay, the load on the station grew to 21,350 MW, way higher than what it could possibly handle. The station blew within seconds, putting a lot more load on whatever system was still feeding Quebec power.
Those systems tripped soon after. The whole James Bay area grid had fallen within a minute!
And that is exactly the trend that large electricity grids follow! Electricity grids are important because electricity, once produced, cannot be stored. Electrical power is immediately consumed and it is critically essential that demand and supply are just equal. Now, consider a huge transmission network carrying power from one substation to a few nearby sub-substations for efficient distributions.
It is important that the sub-substations accept whatever power is being fed to them. Now, say that there is a surge in one of these sub-substation lines, due to either a solar storm or a short circuit. Now, this excess current flow will trip off necessary safety devices, called relays, which will immediately try to regulate the current in the line. That relay might trip if the current is too high and then the excess power being fed to the sub-substation will divert to other sub-substations. These lines will then overload, causing a similar effect of trip and transfer. In fact, the more the system trips, the more the transfer of power, which gives a nasty positive feedback. This runaway or a cascade process leads to the collapse of all connected substations, essentially blacking out a complete grid.
Lesson: In case of a power surge, the grid drops like a series of dominos.
Wait there is more!
Case study 2: Northeast America and Ontario, 2003
In August, 2003, large parts of the Northeastern and Midwestern parts of America and Ontario, Canada faced a large power shortage.
The reason was the failing of a generating plant in Eastlake, Ohio. As the plant went out of operation, the high electrical power demand immediately started sucking power out of the connected lines like leeches. This drainage of excess power caused the transmission lines to overheat (more the current flowing, the more is the heat produced). The overheating caused the wires to sag and it caught some really tall trees, which caused a short circuit. The excess power on this line again caused the familiar cascading failure and the whole grid went bust!
Power was restored to all parts within 20 hours. Most parts regained power within four!
Meanwhile back in India…
It is very safe to bet that something like this has happened in the Indian scenario. The northern states of Haryana, Punjab and Uttar Pradesh were supposedly drawing too much power – much more than what they were entitled to. The reason that this collapse didn’t take place for so long is that the lines could handle much more than what their ratings say. This time something tripped and a spark fell on the tinderbox.
It is mysterious, it kills quickly and it spreads fear and panic. Western Uganda is seeing an outbreak of the deadly Ebola virus, reporting at least 14 dead till yesterday. The deadly virus is seemingly making a comeback to the African country and it has taken doctors quite a while to pin it down going by the symptoms induced in the patients. This is bad news, since this suggests that the recent attack is due to some new strain, unknown or non-existent till now. This means that no medical record or research exists on this particular strain.
The center of the outbreak
The Kibaale district, lying in the center of western Uganda, has been center of the outbreak with people suffering from a mysterious illness in recent weeks. The cause was unknown and many people have left home fearing a disease caused by bad luck or evil spirits. It turns out that reality is worse than that.
The Ebola was confirmed just last night. By today morning, 20 cases have been reported and 14 have died, including a four-month old baby. With no known cure or vaccines, the disease is expected to spread really fast.
Ebola virus causes haemorrhagic fever and kills quickly. The CDC says that the Ebola disease is characterised by “fever, headache, joint and muscle aches, sore throat, and weakness, followed by diarrhoea, vomiting, and stomach pain. A rash, red eyes, hiccups and internal and external bleeding may be seen in some patients”.
The scariest part is how the disease is transmitted. It may be transmitted via bodily secretions and blood. Even the dead is a potential risk. Ebola viruses survive for a long time in the body of the dead after the actual death and funerals can act as mass infecting grounds.
The Medical Organisations
Ugandan officials have been asking the public to keep calm. But that optimism isn’t necessarily shared by all medical organisations. The Center for Disease Control (CDC) are looking for a way to contain this newest attack, which brings back memories of the deadly attack in 2000, which officially left 225 people dead. More recently, a relatively minor outbreak in 2007 left about 40 dead, officially.
The authorities are fearing an epidemic. The spread of any deadly disease is facilitated by time. As more people get infected, the chances of infection rises and the number of people taking care of the infected – the doctors and nurses – also thins out, making it easier for the disease to grow even deadlier.
Diseases sever human relations. As nurses and doctors rightly fear for their lives, the number of patients increases. With diseases like this, the best hope is containment. As callous as it sounds, all we can really do is let the disease die out within a small territory.
In the world of high-powered lasers, a new kid is on the block. And it’s damn powerful! The Berkeley Lab Laser Accelerator (BELLA) has developed a laser which can deliver a huge 1 petawatt of power in a single pulse which lasts for 40 femtoseconds. It can do this once every second, making it a one-pulse-per-second laser.
Now, what do those terms with the funny units mean?
A petawatt is a million billion watts – a quadrillion watts, in everyday language. And a femtosecond is a quadrillionth of a second – one part of 1015 parts in a second! No other laser in the world has this high a peak power and still function at that high a pulse rate (1 pulse per second). This is now officially a world record – this is the world’s most powerful laser.
Building an accelerator
Enter the Laser and Optical Accelerator Systems Integrated Studies (LOASIS) program and there is where BELLA really scores. The really powerful laser is a prototype for the ultimate laser that will be built to accelerate particles for an accelerator. This accelerator will use the laser’s energy to speed up electrons and protons.
Conventional particle accelerators, the LHC included, uses electric fields to accelerate the charged particles, while magnetic fields bend them. The laser uses its intense heat to generate plasma. This plasma has a lot of free electrons swimming around and they can absorb energy and be accelerated to very high speeds. The trick is to make all of these electrons accelerate in phase.
Says Wim Leemans of Berkeley Labs Accelerator and Fusion Research Division (AFRD), the dept. responsible for the construction and maintenance of the LOASIS:
BELLA will be an exceptional tool for advancing the physics of laser and matter interactions. The laser’s peak power will give us access to new regimes, such as developing compact particle accelerators for high-energy physics, and tabletop free electron lasers for investigating materials and biological systems.
BELLA laser will be used to build the world’s first plasma accelerator, which will be able to accelerate electrons to 10 GeV. This is about a thousandths of what the LHC produced, but it’s still very high energy achieved on a device a millionth of the size of the LHC. This successful preliminary test of the BELLA laser was part of the LOASIS test which is due to start this autumn.
Yes, there might be protests as scientists are ‘playing God’ again, but the news is too exciting to stoop to such petty protests. Scientists have mimicked the movement of a mammalian heart and made an artificial jellyfish, which can swim using the exact movements that the heart undergoes when it pumps blood. The body of the jellyfish is made up of silicone with cardiac tissue from a rat mounted on this scaffolding.
Heart and the Jellyfish
The researchers from Harvard University and California Institute of Technology (Caltech) noticed the similarities between the pumping motion of a heart and the pumping motion that helps a jellyfish swim. This is the latest in the emerging field of synthetic biology. Says Kevin Kit Parker, one of the people involved in the study:
I started looking at marine organisms that pump to survive. Then I saw a jellyfish at the New England Aquarium and I immediately noted both similarities and differences between how the jellyfish and the human heart pump.
And thus was born ‘Medusoid’. The main challenge was the lack of understanding of how the heart muscles actually co-ordinate themselves via electrical signals. Then they performed something called ‘reverse engineering’. To understand how a medusa jellyfish really swims and how the muscles are all co-ordinated, the team used techniques from biometrics and crystallography. They were also able to understand the exact biomechanics of the propelling muscle contractions.
Getting everything to work together
It turns out that the mammalian heart muscles move in much the same way when they pump blood. Thus, the plan was to make the jellyfish out of cultured cardiac tissue taken from a rat. Silicone would provide the scaffolding that the structure needed. Then they matched the Medusoid with a real medusa jellyfish, part by part. They made sure that the Medusoid was a copy as long as cellular architecture went.
Less tricky was the design of the silicone structure. They had to ensure that the structure pushed water efficiently, like the jellyfish has evolved to do. Too much gap between the ‘legs’ and water would just ‘leak’ through. Too little and you’d just be wasting precious power for thrusting. The cardiac muscles were stimulated by electrical signals.
The work has been reported in Nature Biotechnology in this paper. Lead author of the paper is Janna Nowroth, a research student. His PhD advisor John Dabiri, an expert of biopropulsion is also an author of the paper. Kevin Kit Parker, another coauthor, is an expert in the field of tissue engineering. He had created artificial ‘organisms’ that can grip and pump. The jellyfish was really ambitious!
So what’s the next step? Endowing the jellyfish with something that even it doesn’t have – a brain. The team wants to put a small control center for the nerves so that it can decide where it wants to go.