Space and astronomy news
If you could travel from world to world, from star to star, out into the gulfs of intergalactic space, you’d move away from the warmth of the stars into the vast and cold depths of the void.
Better pack a sweater, it’s going to get cold.
But, how cold? How cold is space?
Continue reading “How Cold is Space?”
The latest exciting undertaking in exoplanet research is the search for exomoons. A team led by Dr. David Kipping at the Harvard-Smithsonian Center for Astrophysics has jumped at this challenge. After having theoretically proven that detecting an Earth-sized exomoon is possible, the team carried out the first detailed search for an exomoon.
Are you leaning forward on the edge of your seat awaiting the results? Well here you go: the data show no evidence of a moon. That’s simply the luck of the draw. We didn’t discover an exoplanet on our first try either. I believe that this non-detection shows that we’re on the verge of our next greatest discovery.
The reasons for searching for exomoons are abundant. “Exomoons may be frequent, habitable abodes for life and so far we know next to nothing about the underlying frequency of such objects in the cosmos,” Dr. Kipping told Universe Today. “They also play an important role in the habitability of those planets which they orbit, for example the Moon is thought to stabilize the axial tilt of the Earth and so too the climate.”
The project titled “The Hunt of Exomoons with Kepler,” more commonly known as HEK, was formed with these reasons in mind. As such, the HEK project will search for exomoons that are likely to be habitable.
The first target is Kepler-22b – the first transiting exoplanet to have been detected in the habitable zone of its host star. At 2.4 Earth radii, it is too large to be considered an Earth-analog, but it could easily have an Earth-sized moon
There are currently two methods in which we may detect exomoons.
1.) Dynamic effects – the exomoon tugs the planet, which causes deviations in the times and durations of the host planet’s transits. This is similar to the radial velocity technique for detecting exoplanets.
2.) Transit effects – the exomoon may transit the star immediately before or just after the planet does. This will cause an added dip in the observed light. See this video for a great demonstration. This is similar to the light curve technique for detecting exoplanets.
The team modeled the initial transit light curves of Kepler-22b. They then injected an Earth-sized moon into the system in order to analyze the effects. While this caused clear variations in the light curve, such variations had to be above the level of noise.
As such, they also injected noise in the light curves, which mirrors that of the Kepler data. In the end, the variations in a star’s light curve due to the presence of an exomoon are much higher than the noise. The team is able to recover the correct answer with extremely high confidence.
The real data does not show deviations like the previous figure does. This non-detection implies that there is no moon with a mass greater than 0.54 times the mass of the Earth. While there is no Earth-analog in this system, there may be a smaller undetectable moon.
I asked Dr. Kipping about our chances of success in other systems. His answer: “That depends upon nature herself!” We have no idea how regularly nature produces moons in other solar systems. “There is nothing more exciting than working on a project where the answer is wholly unknown.”
But remember: two decades ago we were unsure if nature regularly produced planets. We have since observed them in abundance. I have to believe that with 168 moons in our solar system alone, we’re likely to find them in other systems. We’re on the verge of the next greatest discovery. So stay tuned because I promise I’ll be writing about it when it happens.
Source: Kipping et al. 2013
At 2:38 UTC Tuesday morning (local time) a Russian Proton-M heavy lift rocket carrying three GLONASS navigation/positioning satellites exploded shortly after lifting off from the pad at Baikonur Cosmodrome. The event was captured on a live Russian news feed, seen above.
No word yet on whether there were any injuries or not according to NASASpaceflight.com, no casualties have been reported but the Proton rocket debris may have landed near another pad used by ILS (International Launch Services) — a U.S./Russian joint venture for commercial launches.
According to Anatoly Zak at RussianSpaceWeb.com, “since the emergency cutoff of the first stage engines is blocked during the first 42 seconds of the flight to ensure that the rocket clears the launch complex, the vehicle continued flying with its propulsion system firing practically until the impact on the ground.”
Reminder: space travel is (still) hard.
Update: Watch another view of the failed launch below:
The shockwave at 1:01… yikes.
It’s been 9 years (to the day, in fact) since the Cassini spacecraft first entered orbit around Saturn and ever since it has been sending a steady stream of incredible images from the ringed planet back to Earth, bridging the 900-million-mile distance with countless wonders and groundbreaking discoveries. The views Cassini has provided us of Saturn and its family of moons are unparalleled and unprecedented, but something one could remain in want of is the element of motion: Cassini’s cameras are designed to capture still images, not true video, and thus most of our best views of Saturn are static shots.
That’s where filmmaker Stephen van Vuuren and his current project, “In Saturn’s Rings,” comes in.
An award-winning filmmaker, musician, and photographer (and self-confessed übergeek) from South Africa, Stephen van Vuuren has spent the last several years compiling hundreds of thousands of images acquired by Cassini — as well as other exploration spacecraft — into a single high-definition feature film, one that will allow viewers to experience the beauty, grandeur, and reality of the Solar System like never before.
“In Saturn’s Rings” (formerly “Outside In”) is slated for release in IMAX theaters, planetariums, and museums in the spring of 2014 — and the first official teaser trailer is below, released today. Check it out (or visit the YouTube page to watch in original, eye-melting 4k high-resolution):
“‘In Saturn’s Rings’ is a film that’s both personal and universal, experimental and sincere, science and spirit , non-narrative and documentary. The goal is to use large screen imagery, synchronized to powerful but moving music, to create an experience for those who see it, hear it and feel it.”
– “In Saturn’s Rings” official website
This is one film that I’ll be eagerly looking forward to over the next few months, without a doubt!
Read more on van Vuuren’s official film site here, and check out a full minute of film footage (originally released in 2011) on Vimeo here. Also, you can keep up with updates on the movie’s Twitter and Facebook pages.
KENNEDY SPACE CENTER, FL – NASA is picking up the pace of assembly operations for the Orion capsule, America’s next crew vehicle destined to carry US astronauts to Asteroids, the Moon, Mars and Beyond.
Just over a year from now in September 2014, NASA will launch Orion on its first test flight, an unpiloted mission dubbed EFT-1.
At NASA’s Kennedy Space Center in Florida, expert work crews are already hard at work building a myriad of Orion’s key components, insuring the spacecraft takes shape for an on time liftoff.
In 2014 Orion will blast off to Earth orbit atop a mammoth Delta IV Heavy booster, the most powerful booster in America’s rocket fleet following the retirement of NASA’s Space Shuttle orbiters in 2011.
On later flights Orion will blast off on the gargantuan Space Launch System (SLS), the world’s most powerful rocket which is simultaneously under development by NASA.
At the very top of the Orion launch stack sits the Launch Abort System (LAS) – a critically important component to ensure crew safety, bolted above the crew module.
In case of an emergency situation, the LAS is designed to ignite within milliseconds to rapidly propel the astronauts inside the crew module away from the rocket and save the astronauts lives.
The LAS is one of the five primary components of the flight test vehicle for the EFT-1 mission.
Prior to any launch from the Kennedy Space Center, all the rocket components are painstakingly attached piece by piece.
Final assembly for EFT-1 takes place inside the iconic Vehicle Assembly Building (VAB).
To get a head start on assembly with the launch date relentlessly approaching, technicians have been practicing lifting and stacking techniques for several months inside the VAB transfer aisle using the 6 ton LAS pathfinder replica and mock ups of the Orion crew and service modules.
Conducting the practice sessions now with high fidelity replicas serves multiple purposes, including anticipating and solving problems now before the real equipment arrives, as well as to keep the teams proficient between the years long launch gap between the finale of the Space Shuttle program and the start up of the Orion/SLS deep space exploration program.
Delicate maneuvers like lifting, rolling, rotating, stacking, gimballing and more of heavy components requiring precision placements is very demanding and takes extensive practice to master.
There is no margin for error. Human lives hang in the balance.
The same dedicated crews that assembled NASA’s Space Shuttles inside the VAB for 3 decades are assembling Orion. And they are using the same equipment.
“The breakover, taking the LAS from horizontal to vertical, is not as easy as it sometimes seems, but the VAB guys are exceptional, they are really good at what they do so they really didn’t have a problem,” says Douglas Lenhardt, who is overseeing the Orion mock-up and operations planning for the Ground Systems Development and Operations program, or GSDO.
Simulations with computer models are extremely helpful, but real life situations can be another matter.
“Real-life, things don’t always work perfectly and that’s why it really does help having a physical model,” says Lenhardt.
During the unmanned Orion EFT-1 mission, the capsule will fly on a two orbit test flight to an altitude of 3,600 miles above Earth’s surface, farther than any human spacecraft has gone in 40 years.
I was personally so pumped to have seen the Aurora Borealis over the weekend in Central Minnesota! It was a beautiful display of a green and white glow with high, towering, bright spires. Unfortunately, I was in the car at the time, and I definitely need to upgrade my camera to be able to take images of the aurora. But lucky for us, astrophotographers from both hemispheres captured gorgeous shots of the Aurora Borealis and Aurora Australis.
According to SpaceWeather.com, the Earth passed through a region of south-pointing magnetism in the solar wind on June 28, “and the encounter set off one of the finest geomagnetic storms of the current solar cycle.”
This shot from Colin Chatfield shows the awesome auroral scenes over Saskatchewan.
James Stone from Opossum Bay, Tasmania captured this video of the Aurora Australis:
To see some images from the southern hemisphere, Ian Musgrave has put together a great collection at his Astroblog site.
Can you get good astrophotography shots from within a city? Astrophotographer Bruno Letarte has proved you can capture stunning shots of both city and night sky and turn them into a beautiful timelapse. Last fall we featured a timelapse by Bruno taken at the dark sky site of the South African Large Telescope (SALT), but he said his latest project of shooting among the city lights was a “real learning experience.”
“It was a completely different challenge, much trickier than shooting a perfect dark sky, where you find your optimal exposure time and stick to it for everything,” Bruno told Universe Today via email. “Different objects and different focal lengths, lights in the foreground, moving cars, etc. Many sequences had to be decided on the spot with no time to really think it through.”
He captured various objects (Moon, Sun, planets, comets) either rising or setting against a nice city landscape — with light pollution and all – and all taken with an entry level enthusiast camera.
“It was a real learning experience for me to shoot in these various conditions. It’s also an invitation to the general public to look up in their night sky to see what’s up there, even in a city,” Bruno added. “And for the amateur photographer out there, I’ve included the tech details and comments for each sequences with a few seconds of flashing text.”
A pair of astronomers has proved that we haven’t seen the last of the Herschel Space Observatory! On June 17, 2013, engineers for the Herschel space telescope sent final commands to put the decommissioned observatory into its “graveyard” heliocentric parking orbit, after the liquid helium that cooled the observatory’s instruments was depleted. Now, Nick Howes and Ernesto Guido from the Remanzacco Observatory have used the 2 meter Faulkes Telescope North in Hawaii to take a picture of the infrared observatory as it is moving away from its orbit around the L2 LaGrange Point where it spent the entirety of its mission.
Howes told Universe Today that their observations not only improve future chances of it being seen, but also will help astronomers in that the observatory won’t be mistaken for a new asteroid.
“We saw a potential issue here,” Howes said via email, “as the spacecraft would be in a slow tumble, receding from its stable L2 orbit, subjected to solar radiation pressure. And as ESA’s ground stations were no longer communicating with it, so we wanted to basically check the orbits and make sure that for future science, it was not mistakenly detected as an asteroid.”
When Howes and Guido realized that JPL’s Horizons coordinate system — which generates coordinates for objects in space like Herschel — would be suspending coordinates for the observatory from the end of June, they quickly and urgently used the information they had on Herschel’s movements to make their observations.
“The ephemeris from JPL and the Minor Planet Center varied,” Howes said, “and appeared to show quite different long term positions, so we took the initiative to try to help make sure this orbit was better understood. We knew ESA’s scientists had a pretty good handle on the position, but were perplexed by the variance in the coordinates being generated by the two ephemeris systems”
Radiation pressure and a host of other factors would have and will continue to affect the position of the spacecraft, but with it getting fainter by the day, Howes and Guido made the effort by taking two nights of observations to try and find Herschel as it drifted away from L2.
“Imaging a several metre wide spacecraft at over 2.1 million km from Earth in an orbit that was not quite precise, and a tumbling spacecraft is not an easy task, at the faint magnitudes it theoretically could have been at, ” said Guido, who helps manage the Remanzacco Observatory in Italy. “And while we found what we thought could be it on the first night, our calculations would need to be verified by observing it on a second night to validate that it was indeed Herschel.”
Howes, who’d written about Herschel when working in science communications for ESA, contacted several of the mission team via emails, who gave valuable advice on the effects of the final orbital burn.
“We effectively had three possible locations to hunt in,” Howes said, “and luckily, as rain at one of our telescope sites stopped our plans for the third run, and nothing showed up in our first coordinates, we managed to get it in the second set of images, exactly where we thought it could be, with the correct data for its motion, position angle and other orbital characteristics. Ernesto worked on the data reduction for these images, and after about 30 minutes of frantic discussion, said ‘I think I’ve found it.’”
The team have filed their data with the Minor Planet Center, and have worked closely with astronomers at Kitt Peak, who also imaged the Observatory, further refining the observing arc, passing their coordinates even on to astronomers in Chile, with significantly larger telescopes to get even more images of it.
The Faulkes Telescope Project is based at the University of South Wales, and the telescopes are operated by the Las Cumbres Observatory Global Telescope Network. The telescopes are also used for educational purposes, and schools using the Faulkes Telescope will be able to follow Herschel as she leaves her orbit to wander around the Sun. It will return to our neck of the Solar System around 2027/2028 (astrometry measured by Howes and Guido is factoring in radiation pressure, so the values are approximate), when it will return at around magnitude 21.7.
“We’ve engaged schools in this project as it’s great for learning astrometry, and photometry as well as a fun thing to do, and they’ve also been making animations from our data.”
Howes and Guido hope that the updated information will help others keep an eye on the telescope in the future. “It’s been an exciting week, and we wanted to say thank you to ESA for building such a magnificent telescope,” Howes said. “We just wanted to give it a good send off!”
We don’t put much stock in astrology or horoscopes here at Universe Today, but there’s one thing related to the zodiac that’s all science and no superstition: zodiacal light, captured here in a gorgeous photo by astronomer Alan Fitzsimmons above ESO’s La Silla Observatory.
Created by sunlight reflected off fine particles of dust concentrated inside the plane of the Solar System, zodiacal light appears as a diffuse, hazy band of light visible in dark skies stretching away from a recently-set Sun (or before the Sun is about to rise).
The Moon is located just outside the frame of this picture, bathing the observatory in an eerie light that is reflected off the clouds below.
The La Silla Observatory is located at the outskirts of the Chilean Atacama Desert at an altitude of 2400 meters (7,900 feet). Like other observatories in this area, La Silla is located far from sources of light pollution and, like ESO’s Paranal Observatory, it has some of the darkest night skies on the Earth.
The dome in the foreground, just to the right, is the Swiss 1.2-metre Leonhard Euler Telescope named in honor of the famous Swiss mathematician Leonhard Euler (1707–83).
Image credit: A. Fitzsimmons/ESO
The short answer is, the average distance to the Moon is 384,403 km (238,857 miles). But before you go thinking that this is the final answer, you need to consider a few things. For starters, note the use of the word “average”. This refers to the fact that the Moon orbits around the Earth in an elliptical pattern, which means that at certain times, it will be father away; while at others, it will be closer.
Hence, the number 384,403 km, is an average distance that astronomers call the semi-major axis. At its closest point (known as perigee) the Moon is only 363,104 km (225,622 miles) away. And at its most distant point (called apogee) the Moon gets to a distance of 406,696 km (252,088 miles).
This means that distance from the Earth to the Moon can vary by 43,592 km. That’s a pretty big difference, and it can make the Moon appear dramatically different in size depending on where it is in its orbit. For instance, the size of the Moon can vary by more than 15% from when it’s at its closest to when it’s at the most distant point.
It can also have a dramatic effect on how bright the moon appears when it is in its Full phase. As one might expect, the brightest full Moons occur when the Moon is at the closest, which are typically 30% brighter than when it’s fathest away. When it’s a Full Moon, and it’s a close Moon, it’s known as a Supermoon; which is also known by it technical name – perigee-syzygy.
To get an idea of what this all looks like, check out the animation above that was released by the Goddard Space Flight Center Scientific Visualization Studio in 2011. The animation shows the geocentric phase, libration, position angle of the axis, and apparent diameter of the Moon throughout the year, at hourly intervals.
At this point, a good question to ask would be: how do we know how far away the Moon is? Well, that depends on when we’re talking. In the days of ancient Greece, astronomers relied on simple geometry, the diameter of the Earth – which they had already calculated to be the equivalent of 12,875 km (or 8000 miles) – and the measurements of shadows to make the first (relatively) accurate estimates.
Having observed and recorded how shadows work over a long period of history, the ancient Greeks had determined that when an object is placed in front of the Sun, the length of a shadow this generates will always be 108 times the diameter of the object itself. So a ball measuring 2.5 cm (1 inch) across and placed on a stick between the Sun and the ground will create a triangular shadow that extends for 270 cm (108 inches).
This reasoning was then applied to the phenomena of Lunar and Solar Eclipses.
In the former, they found that the Moon was imperfectly blocked by the shadow of the Earth, and that the shadow was roughly 2.5 times the width of the Moon. In the latter, they noted that the Moon was of sufficient size and distance to block out the Sun. What’s more, the shadow it would create terminated at Earth, and would end in the same angle that the shadow of the Earth does – making them different-sized versions of the same triangle.
Using the calculations on the diameter of the Earth, the Greeks reasoned that the larger triangle would measure one Earth diameter at its base (12,875 km/8000 miles) and be 1,390,000 km (864,000 miles) long. The other triangle would be the equivalent of 2.5 Moon diameters wide and, since the triangles are proportionate, 2.5 Moon orbits tall.
Adding the two triangles together would yield the equivalent of 3.5 Moon orbits, which would create the largest triangle and gave the (again, relatively) accurate measurement of the distance between the Earth and the Moon. In other words, the distance is 1.39 million km (864,000 miles) divided by 3.5, which works out to around 397,500 km (247,000 miles). Not exactly bang on, but not bad for ancient peoples!
Today, millimeter-precision measurements of the lunar distance are made by measuring the time it takes for light to travel between LIDAR stations here on the Earth and retroreflectors placed on the Moon. This process is known as the Lunar Laser Ranging experiment, a process that was made possible thanks to the efforts of the Apollo missions.
When astronauts visited the Moon more than forty years ago, they left a series of retroreflecting mirrors on the lunar surface. When scientists here on Earth shoot a laser at the Moon, the light from the laser is reflected right back at them from one of these devices. For every 100 quadrillion photons shot at the Moon, only a handful come back, but that’s enough to get an accurate appraisal.
Since light is moving at almost 300,000 kilometers (186,411 miles) per second, it takes a little more than a second to make the journey. And then it takes another second or so to return. By calculating the exact amount of time it takes for light to make the journey, astronomers are able to know exactly how far the Moon is at any time, down to millimeter accuracy.
From this technique, astronomers have also discovered that the Moon is slowly drifting away from us, at a glacial rate of 3.8 cm (1.5 inches) a year. Millions of years in the future, the Moon will appear smaller in the sky than it does today. And within a billion years or so, the Moon will be visually smaller than the Sun and we will no longer experience total solar eclipses.
We’ve written many articles about the Moon for Universe Today. Here’s an article about how LCROSS discovered buckets of water on the Moon, and here’s an article about how long it takes to get to the Moon.
If you’d like more info on the Moon, check out NASA’s Solar System Exploration Guide on the Moon, and here’s a link to NASA’s Lunar and Planetary Science page.
We have recorded several episodes of Astronomy Cast about the Moon. Here’s a good one, Episode 113: The Moon, Part 1.