After Chelyabinsk: European experts assess asteroid options

Asteroid Watch.

8 May 2013

In February, a speeding asteroid slammed into our atmosphere and exploded high over Russia’s Ural region, injuring hundreds and causing millions of euros of damage. What should we do if we have a similar – or even bigger – strike in the future?

Of the more than 600 000 known asteroids in our Solar System, almost 10 000 are classified as near-Earth objects, or NEOs, because their orbits bring them relatively close to Earth’s path.

Asteroid trace over Chelyabinsk, Russia, on 15 February 2013

Dramatic proof that any of these can strike Earth came on 15 February, when an unknown object thought to be 17–20 m in diameter arrived at 66 000 km/h and exploded high above Chelyabinsk, Russia, with 20–30 times the energy of the Hiroshima atomic bomb.

The resulting shock wave caused widespread damage and injuries, making it the largest known natural object to have entered the atmosphere since the 1908 Tunguska event, which destroyed a remote forest area of Siberia.

ESA watching out for Earth

“It’s important that we become aware of the current and future position of NEOs, develop estimates on the likelihood of impacts and assess the possible consequences,” says Detlef Koschny, Head of NEO activities in the Agency’s Space Situational Awareness (SSA) Programme Office.

“More importantly, we must consider whether and how warning, mitigation and possible deflection actions can be taken. It’s important not only for Europe, but for the rest of the planet, too.”

One aspect of ESA’s four-year-old effort requires the development of an integrated system to scan the sky nightly for as-yet-undiscovered NEOs.

Artist's impression of asteroids passing Earth

Another important element is studying how mitigation measures can be applied in the case of smaller NEOs, and how to deflect any larger ones that may seriously threaten our home planet.

International experts meeting in Spain

This week, Deimos Space, an industrial partner working for ESA on SSA, has invited top researchers from universities, research institutes, national space agencies and industry in Europe and the USA to discuss the state of the art in NEO impact effects and threat mitigation.

The meeting is taking place in Tres Cantos, Spain, near Madrid.

“A great deal of work remains to be done, for example, in computer modelling of impact effects, how airbursts differ from ground strikes, kinetic versus explosive deflection strategies and much more,” says Gerhard Drolshagen, of the SSA Programme Office.

“The aim is to develop plans that will guide us in current and future NEO research and development.”

Ultimately, ESA aims to develop the capability to integrate European current and new assets such as automated telescopes into a coordinated and more efficient NEO system that can provide nightly sky surveys and advanced warning.

“With this, we can work with our partner agencies, scientists, industry and international bodies like the UN to offer firm options to national governments and political decision-makers,” says Nicolas Bobrinsky, Head of ESA’s SSA Programme.

“Events like the Chelyabinsk strike show that the NEO hazard is not just theoretical, and we need to invest in practical measures today to address tomorrow’s threats.”

Editor’s note: A summary of the workshop findings will be available as a downloadable PDF after 8 May.

Related links:

Workshop on NEO Impact Effects & Threat Mitigation: http://ssasnvii.deimos-space.com/

ESA NEO risk list: http://neo.ssa.esa.int/web/guest/risk-page

Asteroid Impact & Deflection Assessment (AIDA) study: http://www.esa.int/Our_Activities/Technology/NEO/Asteroid_Impact_Deflection_Assessment_AIDA_study

NEO: http://www.esa.int/Our_Activities/Technology/NEO

Images, Text, Credits: ESA / P.Carril / Alex Alishevskikh.

Best regards, Orbiter.ch

International effort helps users get ready for Sentinel-1

ESA - European Space Agency patch.

7 May 2013

Those who need satellite data for a wide range of applications, from mapping sea ice and tracking maritime traffic to monitoring geohazards over land, are eagerly awaiting the launch of Sentinel-1. ESA is helping users get ahead of the game by offering test data and simulated images.

To be launched later this year, Sentinel-1 is the first of five satellite missions dedicated to supplying a stream of data for Europe’s Global Monitoring for Environment and Security ‘Copernicus’ programme.

Vancouver harbour, Canada (click on the image for enlarge)

This particular satellite will provide timely high-quality radar images of our planet’s surface to support European operational services that use Earth observation data in areas such as emergency response, marine and land monitoring, civil security and climate studies.

Getting ready for using Sentinel data is a complex task. The new data format and information structure, the increased data volume, the expected data quality and sensor characteristics all mean that users have to develop or update processing facilities before the launch.

Sentinel-1 satellite

An important step forward in this respect is the availability of simulated products and documentation to users. ESA is responding to these needs in two ways.

Firstly, ESA has just released a sample of Sentinel-1 simulated user products and associated format and product definition documents to GMES users. In addition, the Agency is planning a further distribution to all potential users in the coming weeks.

This first release contains a set of simulated radar intensity ‘Level-1’ products, covering all four Sentinel-1 imaging modes and different product types. An example is shown by way of the image of the Netherlands on the right.

Simulated Sentinel-1 data (click on the image for enlarge)

Notably, these products were generated by a preliminary version of Sentinel-1’s operational Instrument Processing Facility.

Though they are not intended to reflect the final characteristics of the user products, the format and contents are representative of what the mission will offer.

This will evolve with new versions of the facility and may be slightly tuned following system qualification and inflight commissioning.

Joel Dorandeu from MyOcean said, “We very much welcome the efforts being made to help service providers such as us prepare for the new data from Sentinel-1.

“Considering the volumes of data we expect from Sentinel-1 along with its method of acquisition we have the challenge of developing new processing chains.

“We are now eager to start simulating our products."

To complement this initial release of test data, ESA is, in parallel, simulating Sentinel-1 acquisitions from space using Canada’s Radarsat-2 satellite.

Vancouver radar image (click on the image for enlarge)

This initiative is now starting to bear fruit following the first full simulation of a Sentinel-1 radar image as shown in picture at the top and here on the left.

Thanks to its owner and operator, McDonald, Dettwiler and Associates, Radarsat-2 was carefully reprogrammed to match the way Sentinel-1 will be operated. A remarkable achievement is the fact that Radarsat was able to emulate the way Sentinel-1 images Earth’s surface using a method called TOPS, thus providing a quality of image almost exactly the same as Sentinel-1.

The very first results are promising, as can be seen in the images acquired over Vancouver harbour on the west coast of Canada. The city is clearly visible, as are the ships docked in the harbour, the coastline and the nearby mountain ranges.

The acquisition of more images over specific test sites are planned to demonstrate the suitability of Sentinel-1 for classifying sea-ice, for applications using ocean winds and waves, and for detecting ships, thereby preparing users for the uptake of data.

Dedicated acquisitions of image pairs and data stacks suitable for measuring surface movements such as glacier dynamics and subsidence are also planned to take place in the coming months.

As for the current set of test data, the Radarsat-2 simulated images will also be processed and formatted using the Sentinel-1 Instrument Processing Facility and made available to users shortly.

Related missions:

Sentinel-1: http://www.esa.int/Our_Activities/Observing_the_Earth/GMES/Sentinel-1

MDA–Radarsat-2: http://gs.mdacorporation.com/SatelliteData/Radarsat2/Radarsat2.aspx

Related links:

Sentinel-1 simulated products: http://gmesdata.esa.int/web/gsc/news/latest_20130430

European Commission GMES ‘Copernicus’: http://ec.europa.eu/enterprise/policies/space/copernicus/

MyOcean: http://www.myocean.eu/

Images, Text, Credits: ESA / MDA / ATG Medialab.

Cheers, Orbiter.ch

Herschel finds hot gas on the menu for Milky Way’s black hole

ESA - Herschel Mission patch.

7 May 2013

ESA’s Herschel space observatory has made detailed observations of surprisingly hot molecular gas that may be orbiting or falling towards the supermassive black hole lurking at the centre of our Milky Way galaxy.

Our local black hole is located in a region known as Sagittarius A* – Sgr A* – after a nearby radio source. It has a mass about four million times that of our Sun and lies around 26 000 light-years away from the Solar System.

Galactic centre

Even at that distance, it is a few hundred times closer to us than any other galaxy with an active black hole at its centre, making it the ideal natural laboratory to study the environment around these enigmatic objects.

Vast amounts of dust lie in the plane of the Milky Way between here and its centre, obscuring our view at visible wavelengths. But at far-infrared wavelengths, it is possible to peer through the dust, affording Herschel’s scientists the chance to study the turbulent innermost region of our Galaxy in great detail.

Herschel has detected a great variety of simple molecules at the Milky Way’s heart, including carbon monoxide, water vapour and hydrogen cyanide. By analysing the signature from these molecules, astronomers have been able to probe some of the fundamental properties of the interstellar gas surrounding the black hole.

Molecules on the menu at the Milky Way’s black hole

“Herschel has resolved the far-infrared emission within just 1 light-year of the black hole, making it possible for the first time at these wavelengths to separate emission due to the central cavity from that of the surrounding dense molecular disc,” says Javier Goicoechea of the Centro de Astrobiología, Spain, and lead author of the paper reporting the results.

The biggest surprise was quite how hot the molecular gas in the innermost central region of the Galaxy gets. At least some of it is around 1000ºC, much hotter than typical interstellar clouds, which are usually only a few tens of degrees above the –273ºC of absolute zero.

While some of the heating is down to the fierce ultraviolet radiation pouring from a cluster of massive stars that live very close to the Galactic Centre, they are not enough to explain the high temperatures alone.

In addition to the stellar radiation, Dr Goicoechea’s team hypothesise that emission from strong shocks in highly-magnetised gas in the region may be a significant contributor to the high temperatures. Such shocks can be generated in collisions between gas clouds, or in material flowing at high speed from stars and protostars.

“The observations are also consistent with streamers of hot gas speeding towards Sgr A*, falling towards the very centre of the Galaxy,” says Dr Goicoechea. “Our Galaxy’s black hole may be cooking its dinner right in front of Herschel’s eyes.”

Herschel space observatory

Just before material falls into a black hole, it is heated up enormously and can cause high-energy X-ray and gamma-ray flares. While Sgr A* currently shows little sign of such activity, this could change soon.

Using near-infrared observations, other astronomers have spotted a separate, compact cloud of gas amounting to just a few Earth masses spiralling towards the black hole. Located much closer to the black hole than the reservoir of material studied by Herschel in this work, it may finally be gobbled up later this year.

Spacecraft including ESA’s XMM-Newton and Integral will be waiting to spot any high-energy burps as the black hole enjoys its feast.

“The centre of the Milky Way is a complex region, but with these Herschel observations, we have taken an important step forward in our understanding of the vicinity of a supermassive black hole, which will ultimately help improve our picture of galaxy evolution,” says Göran Pilbratt, ESA’s Herschel project scientist.

Notes for Editors

“Herschel Far-Infrared Spectroscopy of the Galactic Center. Hot Molecular Gas: Shocks versus Radiation near Sgr A∗” by J.R. Goicoechea et al., is published inAstrophysical Journal Letters,7 May 2013.

The study focuses on a spectral scan towards Sgr A∗ at wavelengths of approximately 52–671 microns taken with the PACS and SPIRE spectrometers, and is part of the PRISMAS (PRobing InterStellar Molecules with Absorption line Studies) and SPECHIS (SPIRE Spectral Line Surveys of HIFI-GT-KP Sources) Herschel Guaranteed-Time Programmes.

PACS spectra between 52 microns and 190 microns were obtained during March 2011 and March 2012. SPIRE observations between 194 microns and 671 microns were obtained during February 2011.

Herschel launched on 14 May 2009 and completed science observations on 29 April 2013.

Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

Related links:

Herschel overview: http://www.esa.int/Our_Activities/Space_Science/Herschel

Online Showcase of Herschel Images OSHI: http://oshi.esa.int/

Herschel operations: http://www.esa.int/Our_Activities/Operations/Herschel_operations

Herschel in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16

Herschel Science Centre: http://herschel.esac.esa.int/

The Milky Way Project: http://www.milkywayproject.org/

Herschel postcard gallery: http://archives.esac.esa.int/hsa/aio/doc/postcardGallery.html

Images, Text, Credits: ESA / C. Carreau / Radio-wavelength image: National Radio Astronomy Observatory/Very Large Array (courtesy of C. Lang); spectrum: ESA / Herschel / PACS & SPIRE / J.R. Goicoechea et al. (2013).

Best regards, Orbiter.ch

ESA’s Vega launcher scores new success with Proba-V

Arianespace / ESA - Vega VV02 launch poster.


7 May 2013

 Second Vega launch

Second Vega launch by Arianespace a success Proba-V, VNREDSat-1 and ESTCube-1 in orbit.

On Monday, May 6, 2013 at 11:06 pm local time in French Guiana, Arianespace successfully launched the second Vega rocket from the Guiana space Center (CSG), orbiting the Proba-V, VNREDSat-1 and ESTCube-1 satellites.

Vega launch sequence replay

The three solid-propellant stages performed flawlessly and, after two burns of the liquid-propellant upper stage, Proba‑V was released into a circular orbit at an altitude of 820 km, over the western coast of Australia, some 55 minutes into flight.

The satellite is now being controlled by ESA’s centre in Redu, Belgium, where it is undergoing a health check and testing before the operational phase starts to monitor the vegetation coverage on Planet Earth.

Artist's concept of the Proba-V satellite

After releasing Proba-V, the upper stage performed a third burn and the top half of the egg-shaped Vega Secondary Payload Adapter was ejected. After a fourth burn to circularise the orbit at an altitude of 704 km, VNREDSat-1A was released 1 hour 57 minutes into flight. ESTCube‑1 was ejected from its dispenser three minutes later.

Artist's concept of the VNREDSat 1 satellite

A fifth and last burn will now place the spent upper stage on a trajectory that ensures a safe reentry that complies with new debris mitigation regulations.

Second successful Vega launch from CSG

With Ariane 5, Soyuz and now Vega all operating from the Guiana Space Center, Arianespace is the only launch services operator in the world capable of launching all types of payloads into all types of orbits, from the largest to the smallest geostationary satellites, clusters of satellites for constellations and missions to the International Space Station (ISS).

Arianespace / ESA launchers family

Vega is designed to launch payloads in the 1,500 kg class into orbit at an altitude of 700 km, which means that Europe now has a new launcher capable of handling all scientific and government missions, along with commercial launches.

Arianespace has now performed two launches from the Guiana Space Center in 2013, one with the Ariane 5 rocket and one with Vega. Starsem, the company's Euro-Russian joint venture, has also carried out a Soyuz launch in Baikonur, Kazakhstan. From now until the end of the year, Arianespace plans eight more launches from the Guiana Space Center.

For more information about Arianespace, visit: http://www.arianespace.com/index/index.asp

Images, Video, Text, Credits: ESA / P. Carril / Arianespace / EADS Astrium.

Greetings, Orbiter.ch

Satellite Animation Shows Smoke from California’s Springs Fire

NASA / NOAA - GOES-R Mission patch.

April 6, 2013

Video above: A video of smoke from California’s Springs Fire was created by animating satellite imagery from NOAA’s GOES-15 satellite. Animation: NASA GOES Project, NASA Goddard Space Flight Center /Dennis Chesters.

On May 3, 2013, the NOAA GOES infrared and visible imagery were combined to create an animation that showed the plume of smoke from the fire. The smoke plume is seen blowing west and out over the eastern Pacific Ocean. The animation runs 17 seconds and shows the smoke plume from May 3 at 1415 to 2000 UTC (10:15 a.m. to 4 p.m. EDT) was created by the NASA GOES Project, located at NASA's Goddard Space Flight Center, Greenbelt, Md.

California’s Springs Fire still image

According to Reuters news, the Springs Fire has now consumed as much as 28,000 acres of brush in the coastal area located northwest of Los Angeles. The fire started on Thursday, May 2, and by Sunday, May 5, the weather allowed firefighters to put containment lines around the fire.

GOES-15 satellite

NOAA’s GOES-15 or GOES-West satellite sits in a fixed orbit that continually monitors the weather over the western U.S.

Related links:

NOAA - National Oceanic and Atmospheric Administration: http://www.noaa.gov/

GOES Project Science: http://goes.gsfc.nasa.gov/

Images, Text, Credits: NASA's Goddard Space Flight Center / Robert Gutro / NOAA / Boeing.

Best regards, Orbiter.ch

Destination Earth

NASA / ESA - SOHO Mission patch.

6 May 2013

Solar science meets art in this unique portrait of a solar storm heading straight for Earth.

The image above is based on data collected by the ESA/NASA SOHO space observatory during a coronal mass ejection, when a huge cloud of magnetised plasma was ejected from the Sun’s atmosphere and launched towards Earth.

The image shows an extreme-ultraviolet view of the solar disc superimposed on a wide-field view of the surrounding solar environment as the storm leaps away from the Sun.

Two particularly bright regions on the Sun’s face indicate active regions with looping magnetic fields. Towards the left a filament of dense, cool gas appears to snake its way across the surface.

As a result of the ‘running difference’ technique used to process the images, the scene creates a feeling of rapid change as the solar storm expands outwards on all sides of the Sun and races towards us.

The running difference technique takes sequential snapshots and compares them such that the strongest and most persistent features are isolated and highlighted

SOHO spacecraft

Note that the solar disc is not to scale with the background image. SOHO images are usually shown with a gap of around 3 solar radii from the edge of the Sun’s disc, with an occulter blocking out the intense light from the Sun in order to reveal the faint details of the corona.

Coronal mass ejections like the one portrayed here blast away billions of tonnes of matter from the Sun at millions of kilometres per hour. By the time this particular event engulfed Earth two days later, the eruption was some 50 million kilometres wide.

This image featured in a SOHO ‘The Sun as Art’ portfolio in 2002.

Related links:

SOHO overview: http://www.esa.int/Our_Activities/Space_Science/SOHO_overview2

ESA's SOHO science website: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=14

SOHO homepage: http://sohowww.estec.esa.nl/

Hot shots from SOHO: http://sohowww.nascom.nasa.gov/hotshots/

Best of SOHO images: http://sohowww.nascom.nasa.gov/gallery/top10/

SOHO and space weather: http://sohowww.nascom.nasa.gov/spaceweather

What is a 'telemetry keyhole'?: http://sohowww.nascom.nasa.gov/hotshots/2004_01_04/

Images, Text, Credits: SOHO (ESA / NASA) / S. Hill.

Greetings, Orbiter.ch

SolarImpulse Across America 2013: First leg Across America!

SolarImpulse Across America patch.

May 5, 2013

Across America 2013: 1st Leg Take Off

The first leg of the 2013 Across America mission was concluded successfully. Bertrand Piccard did a wonderful job throughout the flight, bringing HB-SIA safely from San Francisco to Phoenix, and landing at 00:30 am MST (UTC-7) on Runway 08, Saturday May 4th.

Across America 2013: Landing in Phoenix

Bertrand had a chance to give numerous interviews to media all around the world before climbing to an altitude above 12,000 ft. where he was then obliged to wear an oxygen mask. Interestingly enough, more people were connected from Japan than the US, for a short while, prior to touchdown.

SolarImpulse landing in Phoenix

Ever thought of flying electric cars? Sure seems we’re not far from that. During the flight Bertrand heard an aircraft asking the Air Traffic Controller (ATC) about Solar Impulse and why he had to remain at a distance. The ATC replied, “Just think of a flying electric car!” cracking Bertrand into a hearty laugh. HB-SIA was extremely well welcomed by all ATC along the way and the exchanges between Bertrand and his ATC interlocutors were very enjoyable. I can imagine how important these exchanges are especially during 20-hour long flights!

Bertrand Piccard was the pilot of this flight

The Solar Impulse team is very excited to spend a few days in Phoenix and we’re hoping to show the plane to as many people as possible. In fact, we were able to organize two days for public visits on Sunday May 5th and Tuesday May 7th between 1 pm and 7 pm. There will be 6 slots per day of one hour each. Given strict airport security regulations, please be aware that a maximum of 150 people are allowed per slot so hurry up and sign up today if you want to get a chance to see the solar airplane!

Just register (http://solarimpulseatphoenixontuesday.eventbrite.com/) for the day and time most convenient to you (Sunday or Tuesday) and come to the airport with your printed ticket.  Parking is available: http://solarimpulse.com/images/Special_Events_Overall_Airport_Map.jpg

For more information about SolarImpulse, visit: http://solarimpulse.com/en/

Images, Video, Text, Credit: SolarImpulse.

Greetings, Orbiter.ch