A "PhoneSat", which is intended to show how ordinary consumer devices can explore space. Credit: NASA Ames Research Center/Dominic Hart
Talk about tiny technology. The NASA PhoneSat 2.4, which is set to launch today (Nov. 19), is so small that the satellite can easy fit in just one of your hands. The agency is quite excited about this second in the series of PhoneSat launches; the first, in April, saw three “smartphone satellites” working in orbit for a week.
PhoneSat is scheduled to launch as a hitchhiker aboard a rocket that will carry the U.S. Air Force Office of Responsive Space ORS-3 mission. The payloads will lift off from the Mid Atlantic Regional Spaceport at NASA’s Wallops Flight Facility in Virginia.
“It’s tabletop technology,” stated Andrew Petro, program executive for small spacecraft technology at NASA Headquarters in Washington.
Andrew Petro, NASA Small Satellite Program executive, holds NASA Smartphone Phonesat replica launched on Antares test flight on April 21, 2013. Credit: Ken Kremer (kenkremer.com)
“The size of a PhoneSat makes a big difference. You don’t need a building, just a room. Everything you need to do becomes easier and more portable. The scale of things just makes everything, in many ways, easier. It really unleashes a lot of opportunity for innovation.”
PhoneSat will be at a higher altitude than its predecessors, NASA added, allowing controllers to gather information on the radiation environment to see how well vital electronics would be affected. In the long run, the agency hopes these tiny machines can be used for Earth science or communications, among other things.
“For example, work is already underway on the Edison Demonstration of Smallsat Networks (EDSN) mission,” NASA stated. “The EDSN effort consists of a loose formation of eight identical cubesats in orbit, each able to cross-link communicate with each other to perform space weather monitoring duties.”
The launch is expected at 7:30 pm EST (12:30 a.m. UTC) and you can follow it on NASA TV.
NASA’s Mars bound MAVEN spacecraft launches atop Atlas V booster at 1:28 p.m. EST from Space Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 18, 2013. Image taken from the roof of the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
KENNEDY SPACE CENTER, FL – NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) space probe thundered to space today (Nov. 18) following a flawless blastoff from Cape Canaveral Air Force Station’s Space Launch Complex 41 at 1:28 p.m. EST atop a powerful Atlas V rocket.
“Hey Guys we’re going to Mars!” gushed Bruce Jakosky, MAVEN’s Principal Investigator at a post launch briefing for reporters.
“Now I am a Martian,” beamed Jakosky gleefully, as well as is everyone else who has worked on MAVEN since the project was conceived some ten years ago, he noted.
Today’s countdown was absolutely perfect culminating in a spectacular and on time lift off that rumbled across the Florida Space Coast to the delight of cheering crowds assembled for the historic launch aimed at discovering the history of water and habitability stretching back over billions of years on Mars.
“I take great pride in the entire team,” said Jakosky.
“Everyone was absolutely committed to making this work.”
MAVEN launches atop Atlas V booster on Nov. 18, 2013 from NASA’s Kennedy Space Center, Florida. Credit: Mike Killian/mikekillianphotography.com
The $671 Million MAVEN spacecraft separated from the Atlas Centaur upper stage some 52 minutes after liftoff, unfurled its wing like solar panels to produce life giving power and thus began a 10 month interplanetary voyage to the Red Planet.
“We’re currently about 14,000 miles away from Earth and heading out to the Red Planet right now,” said MAVEN Project Manager David Mitchell of NASA’s Goddard Space Flight Center at the briefing, after the 5,400-pound spacecraft had been soaring through space for barely two and a half hours.
“The first trajectory correction maneuver (TCM) is set for Dec. 3,” added Mitchell. There are a minimum of four TCM’s to ensure that the majestic probe remains precisely on course for Mars.
“Safe travels MAVEN!” said Mitchell. “We’re with you all the way.”
NASA’s Mars bound MAVEN spacecraft launches atop Atlas V booster at 1:28 p.m. EST from Space Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 18, 2013. Image taken from the roof of the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
It will take the spacecraft 10 months to reach the Red Planet, with arrival scheduled for Sept. 22, 2014.
Jakosky noted that while the launch is a big milestone, it’s just the beginning.
MAVEN’s purpose is to accomplish world class science after arriving at Mars and completing a check-out period before it can finally begin collecting science data.
MAVEN will answer key questions about the evolution of Mars, its geology and the potential for the evolution of life.
“MAVEN is an astrobiology mission,” says Jakosky.
Mars was once wet billions of years ago, but no longer. Now it’s a cold arid world, not exactly hospitable to life.
“We want to determine what were the drivers of that change?” said Jakosky. “What is the history of Martian habitability, climate change and the potential for life?”
MAVEN will study Mars upper atmosphere to explore how the Red Planet may have lost its atmosphere over billions of years. It will measure current rates of atmospheric loss to determine how and when Mars lost its atmosphere and water.
The MAVEN probe carries nine sensors in three instrument suites.
The Particles and Fields Package, provided by the University of California at Berkeley with support from CU/LASP and NASA’s Goddard Space Flight Center in Greenbelt, Md., contains six instruments to characterize the solar wind and the ionosphere of Mars. The Remote Sensing Package, built by CU/LASP, will determine global characteristics of the upper atmosphere and ionosphere. The Neutral Gas and Ion Mass Spectrometer, built by Goddard, will measure the composition of Mars’ upper atmosphere.
“We need to know everything we can before we can send people to Mars,” said Dr. Jim Green, NASA’s Director of Planetary Science at NASA HQ in Washington, DC.
“MAVEN is a key step along the way. And the team did it under budget!” Green elaborated. “It is so exciting!”
Dr. Jim Green (5th from left), NASA’s Director of Planetary Science, poses with MAVEN spacecraft model and space journalists and photographers covering the Nov. 18 MAVEN launch at the Kennedy Space Center – including Ken Kremer (left) from Universe Today/RocketSTEM Media Foundation. Credit: Alan Walters/awaltersohoto.com
Over the course of its one-Earth-year primary mission, MAVEN will observe all of Mars’ latitudes at altitudes ranging from 93 miles to more than 3,800 miles.
MAVEN will execute five deep dip maneuvers during the first year, descending to an altitude of 78 miles. This marks the lower boundary of the planet’s upper atmosphere.
Stay tuned here for continuing MAVEN and MOM news and Ken’s MAVEN launch reports from on site at the Kennedy Space Center press site.
Learn more about MAVEN, MOM, Mars rovers, Orion and more at Ken’s upcoming presentations
Nov 18-21: “MAVEN Mars Launch and Curiosity Explores Mars, Orion and NASA’s Future”, Kennedy Space Center Quality Inn, Titusville, FL, 8 PM
Dec 11: “Curiosity, MAVEN and the Search for Life on Mars”, “LADEE & Antares ISS Launches from Virginia”, Rittenhouse Astronomical Society, Franklin Institute, Phila, PA, 8 PM
Mat Kaplan, Bruce Betts and Emily Lakdawalla on stage for the Planetary Society's launch party for the MAVEN launch. Image via the author.
If you can’t attend a rocket launch live, the next best thing might be watching it on a big screen, surrounded by fellow space fans. Today, as the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft sat atop an Atlas V rocket at Cape Canaveral, space lovers from southern California collected at the Crawford Family Forum in Pasadena California to watch the launch together.
Our friends at the Planetary Society, along with Southern California Public Radio, hosted the free event, and an excited crowd of space enthusiasts of all ages attended the “launch party.”
Mat Kaplan and Bruce Betts converse on the upcoming launch of MAVEN from the Crawford Family Forum in Pasadena, CA
Mat Kaplan and Bruce Betts brought the witty banter that listeners of Planetary Radio are familiar with, while Emily Lakdawalla kept the entire forum current with up-to-the-minute updates of MAVEN in her pre-launch.
Portions of Planetary Radio were recorded during the live broadcast, which gave the audience a treat, actually seeing how the radio program is created for special events such as the launch of a spacecraft.
As the timer counted down to 20 minutes before launch, Casey Dreier called in over the big-screen.
Casey, who’s the Advocacy and Outreach Coordinator of the Planetary Society, was on location at Cape Canaveral with the society’s president, Jim Bell. They both shared their experience leading up to the launch and stressed the need to continue planetary exploration in all of its forms.
Moments after Bell ended the call, Bill Nye, The Science Guy himself, called in to the Crawford Family Forum.
Bill Nye The Science Guy called in with FaceTime minutes before the launch, pointing to the Atlas V rocket in the distance that would give MAVEN the boost it needs to be on her way to Mars.
Replying to Kaplan’s question about excitement of ‘yet another’ Mars mission, Nye exclaimed, “What? How could there be such a thing as just another Mars mission?!” Nye continued on with a fever pitch about just how amazing it is that humans are able to have a presence on another planet, leaving any mission to Mars being nothing short of extraordinary.
As the clock ticked down and the conversation with The Science Guy ended, the official NASA video feed was brought up on the large projection screen for the excited viewers inside the forum.
Even with seconds remaining on the countdown to ignition, Emily — a seasoned Twitter user — remained dedicated to her Twitter followers while up on stage, keeping everyone in the loop about MAVEN’s upcoming explosive boost from the surface of Earth in the direction of the red planet.
remains
At the Atlas V rocket lifts off, starting MAVEN’s journey to Mars, the room erupted in applause. Mat Kaplan commented “Always exciting. Always scary as hell,” as nearly all eyes were fixed on the video footage of the rocket soaring through the sky or their digital devices, getting new information on the rocket’s fate.
While waiting for official word on how the launch was going, the audience was treated to a live version of a Planetary Radio regular segment: Random Space Facts.
Amazingly enough, Bruce wasn’t able to find anything that happened this week in spaceflight history.
Bruce: “In this week in space history… nothing happened.” Mat: “I don’t believe that.” Bruce: “Well, this week MAVEN launched.”
The floor was opened to questions and comments from the audience, allowing children to ask their many questions about the rockets, the spacecraft and what else can be done in Universe. Jim Burke, who worked at Jet Propulsion Laboratory on the Mariner missions commented, “You’re never bored when when you watch a big rocket take off!”
Atlas V “big rocket” launching MAVEN — Photo Credit: David Dickenson (@AstroGuyz)
While MAVEN has her scientific and communication mission ahead of her, it’s easy to conclude that her launch, just like the many that came before her, will inspire people of all ages to at least be more curious as to what’s going on in the Cosmos.
What better way to ensure a better future than to host “launch parties” like this one? The technology is available to allow people from nearly every location on the planet to gather and watch something leave it.
Coming together as a species and residents of this pale blue dot, we can send off our latest mechanical representatives into the Solar System while simultaneously inspiring the youth to embrace their curiosity, creating the future engineers and scientists that bring humanity further into the Universe.
If you missed the live coverage of the launch, here’s the recording, provided by Southern California Public Radio and The Planetary Society:
A view of rivers in Montana, USA, from the ISS. Credit: ESA/Luca Parmitano.
A Canadian camera system aiming to provide near-realtime video views of Earth is readying for a launch from Kazakhstan.
If all goes well, the UrtheCast dual camera system will blast off in a Progress supply ship on Nov. 25, 2013.
This will be the world’s first ever high definition, live-streaming video platform of planet Earth from the International Space Station.
“Imagine you have a nearly live Google Earth, but it isn’t four year old data – you have data that is being refreshed all the time, with videos coming down over interesting areas where interesting events are going on, showing you what is changing, what is going on,” said George Tyc, the Chief Technology Officer at UrtheCast, in an interview with Universe Today earlier this year. “What we really hope to pull off is to change the paradigm, get the everyday person interacting and seeing the data coming down from space to see the Earth and how it is evolving over time in a way that isn’t available right now.”
Last week at the Canadian Space Society Summit, UrtheCast co-founder Wade Larson explained the camera setup will take place in phases, with Phase 1 of the project having two cameras facing the ground, with one having a fixed gaze and the other one featuring maneuverability to points of interest. These should be installed on the station sometime in December 2013, Larson said, with data coming in the first quarter of 2014.
The company’s aim is to make Earth video data more accessible to individuals and schoolchildren, who would log in on UrtheCast’s website, as well as the traditional customers of government and private companies. Additionally, a recent partnership agreement with the UN will see them offer real-time information on dynamic situations such as floods and mass movements of people during humanitarian disasters. They will also be integrating the data with live social media feeds as well as opening up their API for app developers.
The UK covered in snow, as seen on Dec. 8, 2010. Credit: NASA’s Aqua satellite.
Current sponsors on the project from UrtheCast (pronunced “Earthcast”) include Roscosmos, MacDonald, Dettwiler and Associates, the Discovery Channel, Energia, Unosat and RAL Space, Larson added.
The UrtheCast team is working in an exclusive relationship with the Russian Aerospace giant RSC Energia (NASA is not involved at all), and cosmonauts on board the ISS will install the cameras. The video data of the Earth will be down-linked to ground stations around the planet and then displayed in near real time on the UrtheCast web platform.
“We had to meet quite a strict set of requirements that the cameras are safe for cosmonauts and astronauts,” Tyc said, “as there can’t be any toxic substances because they will be inside the ISS before they are installed.”
Tyc added that it will take two spacewalks to do the full installation. The cameras are expected to last at least five years, and Tyc expects them to be up there even longer. “We’re looking at putting additional cameras up there for a second generation, and we expect to be up there for the life of the station, really,” he said.
Tyc said he thinks the social media aspect of UrtheCast will be a big part of the entire experience.
“For example, in a natural disaster or big event we’ll also incorporate videos from the ground of things going on, to experience an event in a far different way than you can now,” he said. “And it’s not being filtered through a media agency — it is what it is – and people can draw their own conclusions and add their own voice.”
Tyc said that if the concept takes off, they think this will be a shift in how people can interact with others around the world. “It could be a feeling of the Overview effect – people who go to space are have a completely changed perspective – we’re trying to bring a little bit of that to the ground,” he said.
The team said the name UrtheCast is a bit of a double entendre, as it is pronounced like “EarthCast” but also looks like “You Are the Cast” since it will be live views of planet Earth.
Once again, we’re heading to Mars! At 18:28 UTC (1:28 p.m. EST), NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft launched successfully from Cape Canaveral Air Force Station in Florida, beginning its 10-month journey to Mars. Launching aboard a United Launch Alliance Atlas V rocket, MAVEN will take critical measurements of the Martian upper atmosphere to help scientists understand climate change over the Red Planet’s history.
We’ll keep the live feed from NASA TV up for a while so you can continue to watch all the post-launch action. If you want to see a replay of the launch, see the video below.
Stay tuned for more details on the launch and post-launch activities!
A full-sized MRI on the International Space Station would take up a lot of size and mass, meaning the astronauts have to use different machines to learn about the body. Here, Russian cosmonaut Gennady Padalka (left) does an ultrasound on NASA astronaut Mike Fincke during Expedition 9 in 2004. Credit: NASA
OTTAWA, CANADA – The University of Saskatchewan hopes to fly a wrist-sized MRI to the International Space Station by 2016 in a standard Progress cargo flight, according to Gordon Sarty, a university professor specializing in medical imaging. Why is this important? It will help doctors keep track of the astronauts’ bone strength on orbit, Sarty says of his team’s invention.
With NASA aiming to run its first one-year mission to the station in 2015, there is renewed emphasis on keeping track of all the nasty things microgravity does to astronauts’ bodies in space. Crew members spend two hours a day exercising, but still come back to Earth having trouble balancing, with weaker bones and muscles, and possible facing changes to organs such as the eyes.
Although NASA runs MRIs on crew members before and after flights, Sarty said the ability to get even a simple scan in orbit would be useful — and quite quick. It would take just five to 10 minutes to perform, and would be simple for anyone to do as the scan would commence at the touch of a button.
There are many ideas for investigating bone health in astronauts. Here, astronaut Doug Wheelock uses an Acoustic Vibration Bone Quality Measurement Device in 2004 during NEEMO 6, one of an underwater series of missions NASA ran to simulate space exploration. Credit: NASA
The Canadian Space Agency is allowed just 44 kilograms (97 pounds) to get the MRI to orbit under its utilization agreement on station (which is based on funding). A full-size MRI able to fit in a standard payload rack would have been about 800 kilograms (1,765 pounds), Sarty said.
Modifications are necessary. Rather than using superconducting magnets to do the work in orbit, Sarty’s design proposes manipulating radio frequency waves instead. (More technical details here.) Sarty’s team currently has a $240,000 grant from the CSA to develop the technology, which goes for about the next year.
Sarty said the International Space Station needs to be outfitted to a “Level 4” standard of medical care, meaning that it would include medical imaging on board to help monitor crew health. NASA’s Human Research Program Utilization Plan for the station (published in 2012) identifies the addition of ultrasound as a boon to ISS’ medical capabilities.
Russian Soyuz spacecraft, docked to the International Space Station. Although Earth is close by for station missions, NASA’s standard of medical care for station has assumed a return to Earth could take days. Credit: NASA.
As for “Level 4”, the NASA Space Flight Human Human System Standard (latest version available expired in 2012) defines Level 4 as “A moderate to high level of potential risk exists that personnel may experience medical problems on orbit. Risk to the mission is greater for medical issues beyond routine ambulatory medicine.” It also assumes a return to Earth can take days. Level 4 applies to Earth, lunar or planetary missions greater than 30 days, but no more than 210 days.
The upside for Earth research? The portable MRI could be repurposed, in a sense, to bring into more remote regions. This is especially true of Canada, where tens of thousands of people live in scattered communities in the remote north.
NGC 3572 seen with a 2.2-meter telescope at the European Southern Observatory's La Silla Observatory in Chile. Credit: ESO/G. Beccari
Star winds are pushing the gas around NGC 3572 into “elephant trunks”, as you can see if you look carefully as this picture snapped by a La Silla Observatory telescope at the European Southern Observatory in Chile. It’s a demonstration of the power of the youngster blue-white stars embedded in the cloud, which are generating huge gusts blowing the gas and dust away from them.
It’s common for young stars to form in groups. After a few million years growing together, their respective gravities pushes everything further apart, and the stars then finish their lifetimes on their own. Looking at young star clusters such as this gives astronomers a better sense about how our own Sun began its life.
If we zoomed closer to those elephant trunks, they would look similar to the famous “Pillars of Creation” image captured in 1995 by the Hubble Space Telescope in the Eagle Nebula (M16). NASA also did a follow-up observation using infrared wavelengths in 2005 and 2011, which made the young stars a bit easier to see amid the gas and dust.
One of the Hubble Space Telescope’s most famous images, the “Pillars of Creation” in the Eagle Nebula. Credit: NASA/ESA
As for the picture of NGC 3572, the high-resolution image from the Wide Field Imager on the MPG/ESO 2.2-metre telescope is also revealing new mysteries that will require further investigation, ESO stated.
“A strange feature captured in this image is the tiny ring-like nebula located slightly above the centre of the image,” ESO wrote. “Astronomers still are a little uncertain about the origin of this curious feature. It is probably a dense leftover from the molecular cloud that formed the cluster, perhaps a bubble created around a very bright hot star. But some authors have considered that it may be some kind of oddly shaped planetary nebula — the remnants of a dying star.”
Astronomers were also surprised by seeing stars older than 10 million years old within this image that were still picking up mass, which implies that planetary formation could take longer than previously believed.
Research was led by ESO astronomer Giacomo Beccari.
NGC 5044 as seen by XMM-Newton. Astronomers say they are able to see hot gas moving in this galaxy because of an interaction with another galaxy millions of years ago. Credit: E. O’Sullivan & ESA
So galaxy group NGC 5044 was just sitting quietly by itself a few million years ago when galaxy NGC 5054 decided to pass right through it. That close encounter finished long ago, but the ricochet is still visible in telescopes as astronomers spotted hot gas rippling through the host galaxy.
“Galaxies are social beasts that are mostly found in groups or clusters – large assemblies of galaxies that are permeated by even larger amounts of diffuse gas. With temperatures of 10 million degrees or more, the gas in galaxy groups and clusters is hot enough to shine brightly in X-rays and be detected by ESA’s XMM-Newton X-ray observatory,” the European Space Agency stated.
“As galaxies speed through these gigantic cauldrons, they occasionally jumble the gas and forge it into lop-sided shapes. An example is revealed in this composite image of the galaxy group NGC 5044, the brightest group in X-rays in the entire sky.”
Fresh observations from XMM-Newton (in blue) are visible in this composite image with other pictures from the Wide-field Infrared Survey Explorer, the Digitized Sky Survey (optical) and Galex (near-ultraviolet).
Publication of this research was accepted in MNRAS and is currently available on prepublishing site Arxiv. The lead author is Ewan O’Sullivan, a visiting scientist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
Comet ISON on Nov. 17 with a tail nearly 8 degrees long and small, highly condensed coma! It looks more like a jet contrail. Credit: Michael Jaeger
Wonderful photos of Comets ISON and Lovejoy with their swollen comas and developing tails have appeared on these pages, but recently, amateur and professional astronomers have probed deeper to discover fascinating dust structures emanating from their very cores. Most comets possess a fuzzy, starlike pseudo-nucleus glowing near the center of the coma. Hidden within this minute luminous cocoon of haze and gas lies the true comet nucleus, a dark, icy body that typically spans from a few to 10 kilometers wide. Comet ISON’s nucleus could be as large as several kilometers and hefty enough (we hope!) to survive its close call with the sun on Nov. 28.
Sketch using Photoshop of the inner region of Comet Lovejoy’s coma showing the false nucleus and the curious dust fountain observed on Nov. 13 in a 15-inch (37-cm) telescope. Credit: Bob King. At right the same plume photographed on Nov. 12 with north up and east to the left. Credit: Luc Arnold
Last Wednesday morning Nov. 13 when calm air allowed a sharp view inside Comet Lovejoy’s large, 15-arc-minute-wide coma I noticed something odd about the false nucleus at low magnification, so I upped the power to 287x for a closer look. Extending from the fuzzy core in the sunward direction was a small cone or fountain-shaped structure of denser, brighter dust shaped like a miniature comet. It stretched eastward from the center and wrapped slightly to the south. Usually it’s harder than heck to see any details within the fuzzy, low-contrast environment of a comet’s coma unless that comet is close to Earth and actively spewing dust and ice. Lovejoy scored on both.
Negative image taken Nov. 14 of Lovejoy’s nucleus and dust fan. North up, west to the right. Credit: Dr. P. Clay Sherrod
By good fortune, Dr. P. Clay Sherrodof the Arkansas Sky Observatories, USA, and Luc Arnold of Saint-Michel-l’Observatoire, France, shared images they’d made at high magnification of the identical feature right at the same time as my own observation. There’s no doubt that what we saw was a jet or combined jets of dust and vapor blasting from Lovejoy’s true nucleus. Jets are linear or fan-shaped features and carry ice, dust and even snowballs from inside the nucleus out into space. They typically form where freshly-exposed ice from breaks or fissures in the comet’s crust vaporizes in the sun’s heat.
What I wouldn’t give to see one up close. Wait – we can. Take a look at the photo of Comet 103P/Hartleymade during NASA’s EPOXI flyby mission in November 2010. Notice that most of Hartley’s crust appears intact with the jets being the main contributors to the dust and gas that form the coma and tail.
Multiple jets were actively spewing ice and dust when NASA’s EPOXI mission zoomed by Comet Hartley 2 in November 2010. The fuzzy spots are balls of fluffy snowballs measuring between 1 inch and 1 foot across. Credit: NASA
Spotting a jet usually requires good seeing (low atmospheric turbulence) and high magnification. They’re low-contrast features but worth searching for in any bright comet. Jets often point toward the sun for good reason – the sunward side of the comet is where the heating is happening. Activity dies back as the comet rotates to face away from the sun during the night and early morning hours. By studying the material streaming away from a comet via jets, astronomers can determine the rotation period of the nucleus.
Nightly images of Comet Hale-Bopp’s rotating nucleus and spiraling jet made March 24-30, 1997 by Brad D. Wallis of JPL. The photos were assembled into this animation by Sky & Telescope
Sometimes material sprayed by jets expands into a curved parabolic hood within the coma. This may explain the wing-shaped structures poking out from Comet ISON’s coma seen in recent photos. Possibly the Nov. 13-14 outburst released a great deal of fresh dust that’s now being pushed back toward the tail by the ever-increasing pressure of sunlight as the comet approaches perihelion.
The inner coma of Comet Hale-Bopp developed a striking series of hoods in March 1997 when a dust jet spewed material night after night from the comet’s rotating nucleus. The animation captures garden sprinkler effect beautifully. Since the nucleus spun around every 11 hours 46 minutes, multiple spiraling waves passed through the coma in the sunward direction. To the delight of amateur astronomers at the time, they were plainly visible through the telescope.
Processed images showing a possible jet extending southeast (PA 150 degrees) of Comet ISON’s nucleus as well as the new wing-like hoods on Nov. 17, 2013. Credit: Denis Buczynski and Nick James of the BAA
When examining a comet, I start at low magnification and note coma shape, compactness and color as well as tail form and length and details like the presence of streamers or knots. Then I crank up the power and carefully study the area around the nucleus. Surprises may await your careful gaze. If Comet ISON does break up, the first sign of it happening might be an elongation or stretching of the false nucleus. If it’s no longer a small, star-like disk or if you notice a fainter, second nucleus tailward of the main, the comet’s days may be numbered.
Another view of the symmetrical “wings” photographed branching from Comet ISON’s coma on Nov. 15. At right, the photo has been specially processed to show the structure more clearly. Credit: Erik Bryssinck
Almost all astronomers agree on the theory of the Big Bang, that the entire Universe is spreading apart, with distant galaxies speeding away from us in all directions. Run the clock backwards to 13.8 billion years ago, and everything in the Cosmos started out as a single point in space. In an instant, everything expanded outward from that location, forming the energy, atoms and eventually the stars and galaxies we see today. But to call this concept merely a theory is to misjudge the overwhelming amount of evidence.
There are separate lines of evidence, each of which independently points towards this as the origin story for our Universe. The first came with the amazing discovery that almost all galaxies are moving away from us.
In 1912, Vesto Slipher calculated the speed and direction of “spiral nebulae” by measuring the change in the wavelengths of light coming from them. He realized that most of them were moving away from us. We now know these objects are galaxies, but a century ago astronomers thought these vast collections of stars might actually be within the Milky Way.
In 1924, Edwin Hubble figured out that these galaxies are actually outside the Milky Way. He observed a special type of variable star that has a direct relationship between its energy output and the time it takes to pulse in brightness. By finding these variable stars in other galaxies, he was able to calculate how far away they were. Hubble discovered that all these galaxies are outside our own Milky Way, millions of light-years away.
So, if these galaxies are far, far away, and moving quickly away from us, this suggests that the entire Universe must have been located in a single point billions of years ago. The second line of evidence came from the abundance of elements we see around us.
In the earliest moments after the Big Bang, there was nothing more than hydrogen compressed into a tiny volume, with crazy high heat and pressure. The entire Universe was acting like the core of a star, fusing hydrogen into helium and other elements.
This is known as Big Bang Nucleosynthesis. As astronomers look out into the Universe and measure the ratios of hydrogen, helium and other trace elements, they exactly match what you would expect to find if the entire Universe was once a really big star.
Line of evidence number 3: cosmic microwave background radiation. In the 1960s, Arno Penzias and Robert Wilson were experimenting with a 6-meter radio telescope, and discovered a background radio emission that was coming from every direction in the sky – day or night. From what they could tell, the entire sky measured a few degrees above absolute zero.
WMAP data of the Cosmic Microwave Background. Credit: NASA
Theories predicted that after a Big Bang, there would have been a tremendous release of radiation. And now, billions of years later, this radiation would be moving so fast away from us that the wavelength of this radiation would have been shifted from visible light to the microwave background radiation we see today.
The final line of evidence is the formation of galaxies and the large scale structure of the cosmos. About 10,000 years after the Big Bang, the Universe cooled to the point that the gravitational attraction of matter was the dominant form of energy density in the Universe. This mass was able to collect together into the first stars, galaxies and eventually the large scale structures we see across the Universe today.
These are known as the 4 pillars of the Big Bang Theory. Four independent lines of evidence that build up one of the most influential and well-supported theories in all of cosmology. But there are more lines of evidence. There are fluctuations in the cosmic microwave background radiation, we don’t see any stars older than 13.8 billion years, the discoveries of dark matter and dark energy, along with how the light curves from distant supernovae.
So, even though it’s a theory, we should regard it the same way that we regard gravity, evolution and general relativity. We have a pretty good idea of what’s going on, and we’ve come up with a good way to understand and explain it. As time progresses we’ll come up with more inventive experiments to throw at. We’ll refine our understanding and the theory that goes along with it.
Most importantly, we can have confidence when talking about what we know about the early stages of our magnificent Universe and why we understand it to be true.
