Category Archives: ESA

Space Weather – Coronal Holes

Here is a look at the coronal hole providing an increase in solar wind and the sporadic aurora

There is a sunspot group now too; called Sunspot 2726 it is about centered on the solar disk (not seen in this image) and a plage in the northern mid-latitudes starting to rotate around the disk.  Aside from being an intensely hot area in the solar chromosphere and can be associated with a sunspot, a plage is a great Scrabble word.

The image shown is from ESA/ROB via helioviewer.org. I encourage you to check out helioviewer.org.

ESA:   This image show dramatic dark areas in the Sun’s corona and was acquired by the SWAP instrument on ESA’s Proba-2 mission at midday on Wednesday, 7 November.

The dark areas are ‘coronal holes’ – areas of open magnetic field in the Sun’s corona that emit charged particles as high-speed solar wind that spreads into space.

When it reaches Earth, this solar wind can affect the functioning of satellites in orbit.

The nice thing is that these are predictable events, as we can see these gaps or holes on the solar disc before the high-speed wind hits Earth.

ESA’s future Lagrange mission will significantly improve our ability to detect these holes and forecast solar wind effects, providing a lead time of three to five days.

Space Weather

If you are out and about after dark and you are in higher latitudes (meaning towards the poles) northern and southern hemisphere and have clear skies keep an eye out for an aurora. We have had sporadic aurora over the past couple days thanks to a coronal hole on the Sun. Disturbances in the geomagnetic field due to strong earthquakes may be another possible aurora source.

ESA: Earth’s magnetosphere is a region of space dominated by our planet’s magnetic field. The magnetosphere protects Earth from most of the solar wind, a flow of charged particles streaming out from the Sun.

However, some particles are able to penetrate this shield and reach the ionosphere, giving rise to space weather effects, including the beautiful polar lights, or auroras, as well as geomagnetic storms. Space weather has a real impact on our activities on Earth, and poses a significant risk to space-farers – robotic and human alike.

Various space missions, including ESA’s Cluster and Swarm, are investigating the magnetic environment around the Earth and how it interacts with the solar wind.

Meanwhile, Sun-watching satellites like the ESA/NASA Solar and Heliospheric Observatory (SOHO), located at the L1 point between Earth and the Sun, monitor coronal mass ejections leaving the Sun and measure the speed of the solar wind 1.5 million km away from our planet, about 1 hour before it reaches Earth.

Image: ESA

European Space Weather Week


The 15th annual European Space Weather Week is here. To that end here is an example of space weather, an aurora, on the planet Uranus.  It will be interesting to see what comes from ESWW this time around.

It’s been quite a while since I’ve seen a proper aurora and it’s likely to be a while until I do. Solar Activity is very low and the Sun for the most part is spotless. You can get a current image and more from a great page maintained by Canadian Amateur Radio Station VE3EN (73 to the op) called SolarHam.com

The great image comes to us from: ESA/Hubble & NASA, L. Lamy / Observatoire de Paris

ESA: On the first day of the 15th annual European Space Weather Week, this image from the NASA/ESA Hubble Space Telescope fittingly shows a striking occurrence of celestial weather in the outer reaches of the Solar System: an aurora on Uranus.

Auroras, also known as polar lights, are a relatively familiar type of space weather to Earth-based stargazers, but have also been spied on many other planets in the Solar System.

Views of the Earth’s Northern and Southern Lights show glowing sheets and rippling waves of bright light painting the sky in striking shades of green and even red, blue, and purple; these breath-taking scenes are created as streams of energetic charged particles hit the upper layers of Earth’s atmosphere at altitudes of up to a few hundreds of kilometres, and interact with resident atoms and molecules of mostly oxygen and nitrogen. These emit photons at specific visible wavelengths or colours – green and red for oxygen, blue and purple for nitrogen – and fill the sky with an eerie auroral glow.

Hubble has observed auroras on Uranus on various occasions: in 2011, when the telescope became the first to image the phenomenon from the vicinity of Earth, then again in 2012 and 2014, taking extra data beyond visible light.

By pointing Hubble’s ultraviolet eye on Uranus twice during the same month, from 1 to 5 and 22 to 24 November 2014, scientists were able to determine that the planet’s glimmering auroras rotate along with the planet. The observations also helped to locate Uranus’ magnetic poles, and allowed scientists to track two so-called interplanetary shocks that propagated through the Solar System. These shocks were triggered by two powerful bursts of material flung out by the Sun via the solar wind, an ongoing flow of charged particles constantly emanating from our star, and caused the most intense auroras ever seen on Uranus.

This image, originally published in 2017, shows the auroras as wispy patches of white against the planet’s azure blue disc, and combines optical and ultraviolet observations from Hubble with archive data from NASA’s Voyager 2 probe. Voyager 2 was the first and only craft to visit the outermost planets in the Solar System; it flew past Uranus in January 1986, and past Neptune in August 1989. These icy planets have not been visited since. NASA and ESA have been studying a possible joint mission that would target the two ice giant planets in order to explore their intriguing role in our planetary system.

European Space Weather Week runs from 5 to 9 November 2018, and brings together engineers, scientists, specialists, and professionals from across the continent in order to exchange news, ideas, and strategies on space weather and protecting Earth’s cosmic environment.

New School Challenges from ESA

Bravo ESA, makes me wish I were a kid again!

ESA:  In the beginning of the World Space Week, ESA is proud to present two new school challenges: Climate Detectives and Moon Camp.

Meant for teams of school students guided by a teacher or educator, Moon Camp and Climate Detectives give young people the chance to run interdisciplinary projects and develop new skills, ranging from science and technology to teamwork and communication, like real space experts would do.

Moon Camp

With Moon Camp, ESA and Airbus Foundation, in partnership with Autodesk, challenge students to take part in the future exploration of space by designing a human shelter on the Moon! The students will have to design a 3D Moon Camp able to sustain the lives of at least two astronauts, taking into account:

  • the use of local resources, such as lunar soil and ice
  • technological solutions, such as power sources, a recycling system, a food growth chamber
  • protection  from meteorites and radiation

The Moon Camp challenge presents two separate categories featuring different levels of complexity:

  • Category 1, for students  up to 12 years old, using the 3D design tool Tinkercad® (free online tool) and
  • Category 2, for students between 13 to 18 years old, using the 3D design tool Fusion 360® (free for students and schools).

Teams can submit their design from 1 November 2018 until 16 March 2019.

Find out more about Moon Camp and help ESA settle on the Moon!

Climate Detectives

Climate detectives

With Climate Detectives ESA challenges students to make a difference in understanding and protecting Earth’s climate.Students will identify a climate problem by observing their local environment and will be tasked to investigate it as Climate Detectives. To this end, they will use available Earth Observation data coming from real satellites, or take measurements on the ground. Based on their investigation, teams will propose a way to help reduce the problem. The students will learn about climate on Earth as a complex and changing system and the importance of respecting our environment.

Climate Detectives is open to teams of students between 8 and 15 years old. The project is deployed in three Phases. Submission for Phase 1 is now open, and it will close on 15 November 2018.

So, do not hesitate any further and find out more about Climate Detectives. ESA needs you to make a difference by protecting Earth’s climate and helping our planet!

Saturn at Opposition from Hubble

A beautiful image of Saturn and some of its moons from the Hubble Space Telescope.

Credit: NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI); CC BY 4.0

Original caption: \Cassini ended its 13-year mission at Saturn on 15 September 2017 when it plunged into the gas giant’s atmosphere, but the NASA/ESA Hubble Space Telescope is still keeping an eye on the ringed planet.

This is a composite image taken by Hubble on 6 June 2018 showing a fully-illuminated Saturn and its rings, along with six of its 62 known moons. The visible moons are (from left to right) Dione, Enceladus, Tethys, Janus, Epimetheus and Mimas (click here for an annotated version). Dione is the largest moon in the picture, with a diameter of 1123 km, compared to the smallest, oddly-shaped Epimetheus with a diameter around 116 km.

During Cassini’s mission, Enceladus was identified as one of the most intriguing moons, with the discovery of water vapour jets spewing from the surface implying the existence of a subsurface ocean. Icy moons with subsurface oceans could potentially offer the conditions to harbour life, and understanding their origins and properties are essential for furthering our knowledge of the Solar System. ESA’s JUpiter ICy moons Explorer (Juice), due to launch in 2022, aims to continue this theme by studying Jupiter’s ocean-bearing moons: Ganymede, Europa, and Callisto.

The Hubble image shown here was taken shortly before Saturn’s opposition on 27 June, when the Sun, Earth and Saturn were aligned so that the Sun fully illuminated Saturn as seen from Earth. Saturn’s closest approach to Earth occurs around the same time as opposition, which makes it appear brighter and larger and allows the planet to be imaged in greater detail.

In this image the planet’s rings are seen near their maximum tilt towards Earth. Towards the end of Cassini’s mission, the spacecraft made multiple dives through the gap between Saturn and its rings, gathering spectacular data in this previously unchartered territory.

The image also shows a hexagonal atmospheric feature around the north pole, with the remnants of a storm, seen as a string of bright clouds. The hexagon-shaped cloud phenomenon is a stable and persistent feature first seen by the Voyager 1 space probe when it flew past Saturn 1981. In a study published just last week, scientists using Cassini data collected between 2013 and 2017, as the planet approached northern summer, identified a hexagonal vortex above the cloud structure, showing there is still much to learn about the dynamics of Saturn’s atmosphere.

The Hubble observations making up this image were performed as part of the Outer Planet Atmospheres Legacy (OPAL) project, which uses Hubble to observe the outer planets to understand the dynamics and evolution of their complex atmospheres. This was the first time that Saturn was imaged as part of OPAL. This image was first published on 26 July.

Anticrepuscular Rays over Southern Tuscany


This glorious image from C) Ollie Taylor (limks below), via ESA illustrates wonderfully one of my favorite things – Atmospheric Optics.

Keep an eye on the sky and you too can see many of the optical effects described in my favorite atmospheric optics site, oddly enough named Atmospheric Optics – check it out and see what you can put to use, I think it’s great fun when it works out. The coolest thing I think I’ve seen and I may have a picture of it is the supernumerary rainbow.

Here is ESA’s caption to this great photo: This panorama comprises five images showing the Sun setting over the medieval and Renaissance town of Montepulciano, southern Tuscany.

While the enormous ball of hot gas that is our star cannot be directly seen, its presence is suggested by the radiant streams of light emanating from below the horizon — called anticrepuscular rays, or antisolar rays.

Despite appearing to meet at a point just below the horizon, the rays are in fact near-parallel beams of sunlight. Similar to the way that parallel railway lines seem to converge at a point in the distance, this is a trick of perspective; while these rays of sunlight do eventually meet at the Sun, it is a great deal further away than they make it appear.

Earth’s atmosphere, made up of gases, particulates and clouds, has shaped the way humans have seen the Sun for as long as they have been able to perceive it, for example making the white-hot star appear yellow against a blue sky, masking the infinite blackness of space.

However, as soon as we get past this protective layer, the true effect of our raging Sun becomes apparent in the fast changing, and potentially harmful environment of space, where space weather rules.

Space weather refers to the environmental conditions in space as influenced by solar activity; besides emitting a continuous stream of electrically charged atomic particles, the Sun periodically emits billions of tonnes of material threaded with magnetic fields in colossal-scale ‘coronal mass ejections’.

These ‘solar sneezes’ can and have caused significant disruption to Earth’s protective magnetic bubble and upper atmosphere, affecting satellites in orbit, navigation systems, terrestrial power grids, and data and communication networks. A recent ESA study estimated the potential impact in Europe from a single, extreme space weather event could be about €15 billion.

For this reason, ESA is planning a new mission to monitor the Sun’s activity and provide early warnings. The spacecraft will be positioned between the Sun and Earth at a special position called the fifth Lagrange point. From here, it can observe the ‘side’ of our star, detecting rapidly changing solar activity before it reaches Earth, providing much-needed warning of extreme weather events, allowing measures to be taken to protect and minimise any possible damage to satellites in orbit or infrastructure on Earth.

More images by UK-based photographer Ollie Taylor can be found on his website, or via Instagram and Facebook.

Remember SMART-1?

2006? My memory is pretty good; I remember this mission vividly including the flash at impact. Just not what year, they all kind of blend together sometimes (LOL).

Anyway, thanks ESA for this remembrance.

ESA: This greyscale, mottled image shows a patch of the Moon’s surface, and features an intriguing shape towards the top of the frame. This was actually made by a spacecraft – it marks the final resting place of ESA’s SMART-1 (Small Missions for Advanced Research in Technology-1).

Launched in 2003, SMART-1 was a Moon-orbiting probe that observed our cosmic companion for roughly three years. On 3 September 2006 the mission’s operations came to an end and the spacecraft was sent down to deliberately crash into the Moon, bouncing and grazing across the lunar surface at a speed of two kilometres per second and achieving Europe’s first lunar touchdown.

After the impact, a bright flash was seen at the boundary between lunar day and night by the Canada-France-Hawaii Telescope in Hawaii. However, as no other spacecraft were currently in orbit at the time to watch the event unfurl, it was not possible to pinpoint exactly where SMART-1 crashed. Scientists used orbit tracking, Earth-based simulations, and observations of the bright impact flash to estimate the location of the landing site, but the mission’s precise resting place remained unknown for over a decade.

Last year, high-resolution images from NASA’s Lunar Reconnaissance Orbiter (LRO) revealed the whereabouts of SMART-1 – as shown here. The spacecraft carved out a four-metre-wide and 20-metre-long gouge as it it impacted and bounced at 34.262° south, 46.193° west. It cut across a small crater and sent lunar soil flying outwards from its skidding, ricocheting path, creating the brighter patches of material seen either side of the crater, with debris from spacecraft and oblique dust ejecta coming to a halt several to tens of kilometres in the forward stream direction.

Alongside searching for water ice on the Moon and observing and photographing our nearest celestial neighbour, SMART-1 played a key role in testing ion propulsion – an efficient type of propulsion that uses electrical energy to propel a spacecraft through space.

SMART-1 was ESA’s first mission to travel to deep space using this type of propulsion. Ion propulsion will also be used on the joint ESA-JAXA BepiColombo mission when it launches in October of this year towards Mercury.

The field of view in the image is 50 metres wide (north is up), with solar illumination coming from the west. SMART-1 touched down from north to south.

More about SMART-1

Copyright P. Stooke/B. Foing et al 2017/ NASA/GSFC/Arizona State University

Wind and Water

First the wind, this is how ESA’s Aeolus satellite will use laser technology to measure the winds to help understand our climate and to improve our weather forecasts.

Next the water, an ESA-backed group, led by TCarta, has developed a way of using data from Low-orbiting satellites equipped with light-measuring sensors to produce water depth maps AND make them available to anyone who could use them.

Both videos copyright by ESA.

Gaia’s Star Density Map

A star density map composed by data obtained from second data release of Gaia – not to mention a very resourceful individual.

ESA: The second data release of ESA’s Gaia mission, made in April, has marked a turning point in the study of our Galactic home, the Milky Way. With an unprecedented catalogue of 3D positions and 2D motions of more than a billion stars, plus additional information on smaller subsets of stars and other celestial sources, Gaia has provided astronomers with an astonishing resource to explore the distribution and composition of the Galaxy and to investigate its past and future evolution.

The majority of stars in the Milky Way are located in the Galactic disc, which has a flattened shape characterised by a pattern of spiral arms similar to that observed in spiral galaxies beyond our own. However, it is particularly challenging to reconstruct the distribution of stars in the disc, and especially the design of the Milky Way’s arms, because of our position within the disc itself.

This is where Gaia’s measurements can make the difference.

This image shows a 3D map obtained by focusing on one particular type of object: OB stars, the hottest, brightest and most massive stars in our Galaxy. Because these stars have relatively short lives – up to a few tens of million years – they are mostly found close to their formation sites in the Galactic disc. As such, they can be used to trace the overall distribution of young stars, star formation sites, and the Galaxy’s spiral arms.

The map, based on 400,000 of this type of star within less than 10 000 light-years from the Sun, was created by Kevin Jardine, a software developer and amateur astronomer with an interest in mapping the Milky Way using a variety of astronomical data.

It is centred on the Sun and shows the Galactic disc as if we were looking at it face-on from a vantage point outside the Galaxy.

To deal with the massive number of stars in the Gaia catalogue, Kevin made use of so-called density isosurfaces, a technique that is routinely used in many practical applications, for example to visualise the tissue of organs of bones in CT scans of the human body. In this technique, the 3D distribution of individual points is represented in terms of one or more smooth surfaces that delimit regions with a different density of points.

Here, regions of the Galactic disc are shown with different colours depending on the density of ionising stars recorded by Gaia; these are the hottest among OB stars, shining with ultraviolet radiation that knocks electrons off hydrogen atoms to give them their ionized state.

The regions with the highest density of these stars are displayed in pink/purple shades, regions with intermediate density in violet/light blue, and low-density regions in dark blue. Additional information from other astronomical surveys was also used to map concentrations of interstellar dust, shown in green, while known clouds of ionised gas are depicted as red spheres.

The appearance of ‘spokes’ is a combination of dust clouds blocking the view to stars behind them and a stretching effect of the distribution of stars along the line of sight.

An interactive version of this map is also available as part of Gaia Sky, a real-time, 3D astronomy visualisation software that was developed in the framework of the Gaia mission at the Astronomisches Rechen-Institut, University of Heidelberg, Germany.

Further details including annotated version of the map: Mapping and visualising Gaia DR2

Credits: Galaxy Map / K. Jardine