Welcome to another edition of Constellation Friday! Today, in honor of the late and great Tammy Plotner, we take a look at “the Twins” – the Gemini constellation. Enjoy!
In the 2nd century CE, Greek-Egyptian astronomer Claudius Ptolemaeus (aka. Ptolemy) compiled a list of the then-known 48 constellations, the sum of thousands of years’ worth of charting the heavens. This treatise, known as the Almagest, would be used by medieval European and Islamic scholars for over a thousand years to come, effectively making it the astrological and astronomical canon until the early Modern Age.
One of the original 48 is Gemini, a constellation located on the ecliptic plane between Taurus (to the west) and Cancer (to the east). Its brightest stars are Castor and Pollux, which are easy to spot and represent the “Twins,” hence the nickname. Gemini is bordered by the constellations of Lynx, Auriga, Taurus, Orion, Monoceros, Canis Minor, and Cancer. It has since become part of the 88 modern constellations recognized by the International Astronomical Union.
What does it take to have the “Right Stuff” to become an Astronaut?
Are you an overachiever? Are you working on multiple PhDs in obscure and difficult topics? Can you speak multiple languages, including alienese? Do you suspect, if handed the controls, you could complete the Kessel Run in fewer parsecs than Han Solo?
If you said yes to any of these questions you might want to consider becoming an astronaut. In fact, if you’re an American citizen, there’s never been a better time to see if you’ve got the right stuff. NASA has opened up their astronaut corps to the few, the proud, the willing to get motion sickness in zero gravity. To boldly vomit where few have vomited before.
In the olden days, you either had to be a chimpanzee or an Air Force test pilot to be allowed to take the controls of a genuine NASA rocket and break free from the surly chains of gravity. When NASA finally upgraded its astronaut corps from chimps to humans in the 1950s to begin the Mercury program, they decided they’d only allow test pilots to apply for the first missions.
To fit in the cramped cabin, you had to physically be no taller than 180 cm (5’ 11”), and weigh no more than 82 kg (180 pounds). You needed to have book smarts, too. Astronaut candidates needed at least a bachelor’s degree or the equivalent, but still be under 40 years old. But most importantly, you had to be a test pilot with at least 1,500 hours of flying time and the ability to fly jets.
If you didn’t have hours behind the stick, piloting the most insane flying machines dreamt up by those nutty scientists, well then you didn’t have the right stuff.
Those qualifications continued through the Gemini and Apollo program, although, they relaxed them somewhat, allowing younger astronauts, and those with less flight time. In the recruitment of astronauts in 1965, they allowed a new class of scientist-astronauts; folks with science degrees and no flight time. The most famous of these was Jack Schmitt, a geologist who walked on the Moon with Apollo 17.
NASA now understands that they need astronauts with a wide range of space-based skills, and not just a bunch of test pilots. There are two kinds of people who get to go to space: pilots and mission specialists.
The first category are the commanders and pilot astronauts – the folks who actually fly the spacecraft. They’re the ones with thousands of hours behind the stick of a modern jet, the more cockamamie the better.
To be qualified as a pilot astronaut, you need to have at least 1,000 hours of pilot-in-command time in a jet aircraft. You need to be healthy, with normal blood pressure, good vision and a height between 158 – 191 cm (62 and 75 inches). There are no longer any age restrictions, so astronauts have been selected between 26 and 46 years old.
You need a degree in some kind of space-related science, like engineering, mathematics, biological science and physical science. But that’s a minimum. You really want to have an advanced degree, or even multiple degrees. So, if you’re a healthy, eagle-eyed test pilot with a few advanced degrees, you should apply.
The other category is the mission specialists. These are the astronauts with specialties that will come into play on a space mission. For example: doctors, engineers, particle physicists, xenobiologists, alien translators, droid mechanics, etc. Since you won’t be required to fly the spacecraft, test pilot experience isn’t necessary, but you’ll need to have the same physical health as the pilot astronaut.
The main difference is that you’ll need to have one or multiple advanced degrees in engineering, science or math. The more degrees, and the more advanced they are, the better. Gotta collect them all.
I mentioned two kinds of astronauts, but there’s actually a third – the payload specialist. These were the astronauts who went to space during the shuttle era to support a specific mission. Priority was given to qualified NASA astronauts, but this was also how foreign astronauts like Canada’s Marc Garneau got a chance to fly in space.
Are you intrigued and thinking you might want to throw your name in the helmet? Want to know what being an astronaut pays? A starting astronaut can make $66,000 per year, while a senior one can earn $145,000 per year. Not bad at all, and the view from your office is spectacular.
So, if you’re a US citizen, you meet the qualifications, and you’d like to fly to space, you should apply during this latest call for candidates. And if you don’t think you make the cut, go ahead and wrap up those PhDs, as there’ll be another astronaut selection in a few years.
And if you do apply and don’t make the cut this time around, don’t despair. From the astronauts I’ve talked to, sometimes it takes a few applications before you get accepted. Persistence pays off.
Well, are you going to sign up and become an astronaut? Where do you think your mission will go? Tell us in the comments below.
Wouldn’t it be nice if a meteor shower peaked on a weekend instead of 3 a.m. Monday morning? Maybe even showed good activity in the evening hours, so we could get our fill and still get to bed at a decent hour. Wait a minute – this year’s Geminids will do exactly that!
What’s more, since the return of this rich and reliable annual meteor shower occurs around 6 a.m. (CST) on Sunday December 14th, both Saturday and Sunday nights will be equally good for meteor watching. After the Perseids took a battering from the Moon last August, the Geminids will provide the best meteor display of 2014. They do anyway! The shower’s been strengthening in recent years and now surpasses every major shower of the year.
The official literature touts a rate of 120 meteors per hour visible from a dark sky site, but I’ve found 60-80 per hour a more realistic expectation. Either way, what’s to complain?
The third quarter Moon rises around midnight Saturday and 1 a.m. on Monday morning. Normally, moonlight would be cause for concern, but unlike many meteor showers the Geminids put on a decent show before midnight. The radiant, the location in the sky from which the meteors will appear to stream, will be well up in the east by 9:30 p.m. local time. That’s a good 2-3 hours of meteor awesomeness before moonrise.
Shower watching is a total blast because it’s so simple. Your only task is to dress warmly and get comfortable in a reclining chair aware from the unholy glare of unshielded lighting. The rest is looking up. Geminid meteors will flash anywhere in the sky, so picking a direction to watch the shower isn’t critical. I usually face east or southeast for the bonus view of Orion lumbering up from the horizon.
Bring your camera, too. I use a moderately wide angle lens (24-35mm) at f/2.8 (widest setting), set my ISO to 800 or 1600 and make 30-second exposures. The more photos you take, the better chance of capturing a meteor. You can also automate the process by hooking up a relatively inexpensive intervalometer to your camera and have it take the pictures for you.
As you ease back and let the night pass, you’ll see other meteors unrelated to the shower, too. Called sporadics, they trickle in at the rate of 2-5 an hour. You can always tell a Geminid from an interloper because its path traces back to the radiant. Sporadics drop down from any direction.
Geminid meteors immolate in Earth’s atmosphere at a moderate speed compared to some showers – 22 miles per second (35 km/sec) – and often flare brightly. Green, red, blue, white and yellow colors have been recorded, making the shower one of the more colorful. Most interesting, the meteoroid stream appears to be sorted according to size with faint, telescopic meteors maxing out a day before the naked eye peak. Larger particles continue to produce unusually bright meteors up to a few days after maximum.
Most meteor showers are the offspring of comets. Dust liberated from vaporizing ice gets pushed back by the pressure of sunlight to form a tail and fans out over the comet’s orbital path. When Earth’s orbit intersects a ribbon of this debris, sand and gravel-sized bits of rock crash into our atmosphere at high speed and burn up in multiple flashes of meteoric light.
But the Geminids are a peculiar lot. Every year in mid-December, Earth crosses not a comet’s path but that of 3200 Phaethon (FAY-eh-thon), a 3.2 mile diameter (5.1 km) asteroid. Phaethon’s elongated orbit brings it scorchingly close (13 million miles) to the Sun every 1.4 years. Normally a quiet, well-behaved asteroid, Phaethon brightened by a factor of two and was caught spewing jets of dustwhen nearest the Sun in 2009, 2010 and 2012. Apparently the intense heat solar heating either fractured the surface or heated rocks to the point of desiccation, creating enough dust to form temporary tails like a comet.
While it looks like an asteroid most of the time, Phaethon may really be a comet that’s still occasionally active. Periodic eruptions provide the fuel for the annual December show.
Most of us will head out Saturday or Sunday night and take in the shower for pure enjoyment, but if you’d like to share your observations and contribute a bit of knowledge to our understanding of the Geminids, consider reporting your meteor sightings to the International Meteor Organization. Here’s the link to get started.
And this just in … Italian astronomer Gianluca Masi will webcast the shower starting at 8 p.m. CST December 13th (2 a.m. UT Dec. 14) on his Virtual Telescope Project site.
Space is a dangerous and sometimes fatal business, but happily there were moments where a situation happened and the astronauts were able to recover.
An example: today (March 16) in 1966, Neil Armstrong and Dave Scott were just starting the Gemini 8 mission. They latched on to an Agena target in the hopes of doing some docking maneuvers. Then the spacecraft started spinning inexplicably.
They undocked and found themselves tumbling once per second while still out of reach of ground stations. A thruster was stuck open. Quick-thinking Armstrong engaged the landing system and stabilized the spacecraft. This cut the mission short, but saved the astronauts’ lives.
Here are some other scary moments that astronauts in space faced, and survived:
Friendship 7: False landing bag indicator (1962)
John Glenn was only the third American in space, so you can imagine the amount of media attention he received during his three-orbit flight. NASA received an indication that his landing bag had deployed while he was still in space. Friendship 7’s Mercury spacecraft had its landing cushion underneath the heat shield, so NASA feared it had ripped away. Officials eventually informed Glenn to keep his retrorocket package strapped to the spacecraft during re-entry, rather than jettisoning it, in the hopes the package would keep the heat shield on. Glenn arrived home safely. It turned out to be a false indicator.
Apollo 11: Empty fuel tank (1969)
Shortly after Neil Armstrong announced “Houston, Tranquility Base, here, the Eagle has landed” during Apollo 11, capsule communicator Charlie Duke answered, “Roger, Tranquility. We copy you on the ground. You got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot.” They weren’t holding their breath just because it was the first landing on the moon; Armstrong was navigating a spacecraft that was almost out of fuel. The spacecraft Eagle overshot its landing and Armstrong did a series of maneuvers to put it on relatively flat ground. Accounts say he had less than 30 seconds of fuel when he landed on July 20, 1969.
Apollo 12: Lightning strike (1969)
Moments after Apollo 12 headed from ground towards orbit, a lightning bolt hit the rocket and caused the spacecraft to go into what appeared to be a sort of zombie mode. The rocket was still flying, but the astronauts (and people on the ground) were unsure what to do. Scrambling, one controller suggested a command that essentially reset the spacecraft, and Apollo 12 was on its way. NASA did take some time to do some double-checking in orbit, to be sure, before carrying on with the rest of the mission. The agency also changed procedures about launching in stormy weather.
Apollo 13: Oxygen tank explosion (1970)
The astronauts of Apollo 13 performed a routine stir of the oxygen tanks on April 13, 1970. That’s when they felt the spacecraft shudder around them, and warning lights lit up. It turned out that an oxygen tank, damaged through a series of ground errors, had exploded in the service module that fed the spacecraft Odyssey, damaging some of its systems. The astronauts survived for days on minimal power in Aquarius, the healthy lunar module that was originally supposed to land on the moon. They arrived home exhausted and cold, but very much alive.
Apollo-Soyuz Test Project: Toxic vapours during landing (1975)
The Apollo-Soyuz Test Project was supposed to test out how well American and Russian systems (and people) would work together in space. Using an Apollo command module and a Russian Soyuz, astronauts and cosmonauts met in orbit and marked the first mission between the two nations. That almost ended in tragedy when the Americans returned to Earth and their spacecraft was inadvertently flooded with vapours from the thruster fuel. “I started to grunt-breathe to make sure I got pressure in my lungs to keep my head clear. I looked over at Vance [Brand] and he was just hanging in his straps. He was unconscious,” recalled commander Deke Slayton, in a NASA history book about the event. Slayton ensured the entire crew had oxygen masks, Brand revived quickly, and the mission ended shortly afterwards.
Mir: The fire (1997)
The crew on Mir was igniting a perchlorate canister for supplemental oxygen when it unexpectedly ignited. As they scrambled to put out the fire, NASA astronaut Jerry Linenger discovered at least one oxygen mask on board were malfunctioning as well. The crew managed to contain the fire quickly. Even though it affected life aboard the station for a while afterwards, the crew survived, did not need to evacuate, and helped NASA learn lessons that they still use aboard the International Space Station today.
STS-51F: Abort to orbit (1985)
The crew of space shuttle Challenger endured two aborts on this mission. The first one took place at T-3 seconds on July 12, when a coolant valve in one of the shuttle’s engines malfunctioned. NASA fixed the problem, only to face another abort situation shortly after liftoff on July 29. One of the engines shut down too early, forcing the crew to abort to orbit. The crew was able to carry on its mission, however, including many science experiments aboard Spacelab.
STS-114: Foam hitting Discovery (2005)
When Discovery lifted off in 2005, the fate of the entire shuttle program was resting upon its shoulders. NASA had implemented a series of fixes after the Columbia disaster of 2003, including redesigning the process that led to foam shedding off Columbia’s external tank and breaching the shuttle wing. Wayne Hale, a senior official in the shuttle program, later recalled his terror when he heard of more foam loss on Discovery: “I think that must have been the worst call of my life. Once earlier I had gotten a call that my child had been in an auto accident and was being taken to the hospital in an ambulance. That was a bad call. This was worse.” The foam, thankfully, struck nothing crucial and the crew survived. NASA later discovered the cracks in the foam are linked to changes in temperature the tank undergoes, and made more changes in time for a much more successful mission in 2006.
We’ve probably missed some scary moments in space, so which ones do you recall?
NASA has published a new online gallery of beautifully restored photographs from the historic Project Gemini of the 1960s, the second U.S. manned spaceflight program. The digitally remastered photos have been scanned from the original film, showing highlights of Project Gemini in beautifully enhanced colour and detail.
Project Gemini followed the initial Project Mercury program and was the predecessor for the ambitious Apollo missions to the Moon, with ten crewed flights from 1965-1966. It used a two-man spacecraft and tested new technologies and procedures for the later Apollo missions such as precision atmospheric reentry, Extra Vehicular Activity (spacewalking), fuel cells to generate electricity and water, perfect the rendezvous and docking process between two spacecraft, new techniques for propelling and maneuvering two docked spacecraft and long-term human spaceflight.
It featured the first spacewalk, the first rendezvous between two Gemini spacecraft, the first docking between a manned and unmanned vehicle, the first maneuver to change orbit and the first onboard computer.
The photo gallery is part of the March to the Moon website archive, which also has restored photo galleries from the Mercury missions as well as background information on the missions, Quicktime video clips and links to additional resources.
About 2,000 light-years away, in the constellation of Cygnus (the Swan), lies Sharpless 2-106 (after Stewart Sharpless who put the catalog together in 1959), the birth-place of a star cluster-to-be.
Two recent image releases – by Subaru and Gemini – showcase their new filter sets and image capabilities; they also reveal the stunning beauty of the million-year-long process of the birth of a star.
The filter set is part of the Gemini Multi-Object Spectrograph (GMOS) toolkit, and includes ones centered on the nebular lines of doubly ionized oxygen ([OIII] 499 nm), singly ionized sulfur ([SII] 672 nm), singly ionized helium (HeII 468nm), and hydrogen alpha (Hα 656 nm). The filters are all narrowband, and are also used to study planetary nebulae and excited gas in other galaxies.
The hourglass-shaped (bipolar) nebula in the new Gemini image is a stellar nursery made up of glowing gas, plasma, and light-scattering dust. The material shrouds a natal high-mass star thought to be mostly responsible for the hourglass shape of the nebula due to high-speed winds (more than 200 kilometers/second) which eject material from the forming star deep within. Research also indicates that many sub-stellar objects are forming within the cloud and may someday result in a cluster of 50 to 150 stars in this region.
The nebula’s physical dimensions are about 2 light-years long by 1/2 light-year across. It is thought that its central star could be up to 15 times the mass of our Sun. The star’s formation likely began no more than 100,000 years ago and eventually its light will break free of the enveloping cloud as it begins the relatively short life of a massive star.
For this Gemini image four colors were combined as follows: Violet – HeII filter; Blue – [SII] filter; Green – [OIII] filter; and Red – Hα filter.
The Subaru Telescope image was made by combining images taken through three broadband near-infrared filters, J (1.25 micron), H (1.65 micron), and K’ (2.15 micron).
An artist’s rendition of colliding planets, the most likely explanation for the warm dust observed around HD 131488. Image credit: Lynette Cook for Gemini Observatory/AURA
Five-hundred light years away, worlds are colliding, and they’re made of nothing we’ve ever seen.
Last week at the 215th American Astronomical Society meeting, UCLA astronomers announced that they had found warm dust – evidence for the violent collision of rocky planets – around a star called HD 131488. The strange thing is, the composition of the dust has little in common with the composition of rocky bodies in any other known system.
“Typically, dust debris around other stars, or our own Sun, is of the olivine, pyroxene, or silica variety, minerals commonly found on Earth,” said Dr. Carl Melis, who led the research as a graduate student at UCLA. “The material orbiting HD 131488 is not one of these dust types. We have yet to identify what species it is – it really appears to be a completely alien type of dust.”
The warm dust in the HD 131488 system is concentrated in an area close to the star, where temperatures are similar to those on Earth. The researchers concluded that the most likely source for dust in that part of the system would be the collision of two rocky planetary bodies. Only five other stars like HD 131488 with dust in their terrestrial planet zone are known. “Interestingly, all five of these stars have ages in the range of 10-30 million years,” Melis said. “This finding indicates that the epoch of final catastrophic mass accretion for terrestrial planets, the likes of which could have resulted in the formation of the Earth-Moon system in our own Solar System, occurs in this narrow age range for stars somewhat more massive than the Sun.”
The team also discovered a unique second dusty region in the outer reaches of the HD 131488 system, comparable to the location of Pluto and other Kuiper Belt objects in our own solar system.
Top: Illustration depicting the location of the warm and cold dust rings in the HD131488 system. Bottom: Comparable regions in our own solar system, with the orbits of the outer planets for scale. Image Credit: Lynette Cook for Gemini Observatory/AURA
“The hot dust almost certainly came from a recent catastrophic collision between two large rocky bodies in HD 131488’s inner planetary system,” Melis said. “The cooler dust, however, is unlikely to have been produced in a catastrophic collision and is probably left over from planet formation that took place farther away from HD 131488.”
“…for some reason stars that have large amounts of orbiting warm dust do not also show evidence for the presence of cold dust. HD 131488 dramatically breaks this pattern,” said Dr. Benjamin Zuckerman, a co-author on the paper and a professor of physics and astronomy at UCLA.
With its unusual dust composition and unique combination of warm and cold dust regions, the HD 131488 system is now under intense scrutiny. Melis and colleagues plan to continue trying to determine the composition of the dust, and will search for other stars with the dusty evidence for planet formation.