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.

Jupiter’s Clouds

It’s been a while since I shared some of the great images coming from the public using the JunoCam data, so here you go. Very nice work!

NASA: Intricate swirls in Jupiter’s volatile northern hemisphere are captured in this color-enhanced image from NASA’s Juno spacecraft. Bursts of bright-white “pop-up” clouds appear scattered throughout the scene, with some visibly casting shadows on the neighboring cloud layers beneath them. Juno scientists are using shadows to determine the distances between cloud layers in Jupiter’s atmosphere, which provide clues to their composition and origin.

This image was taken at 10:27 p.m. PDT on May 23, 2018 (1:27 a.m. EDT on May 24) as the spacecraft performed its 13th close flyby of Jupiter. At the time, Juno was about 7,050 miles (11,350 kilometers) from the planet’s cloud tops, above a northern latitude of approximately 49 degrees.

Citizen scientists Gerald Eichstädt and Seán Doran created this image using data from the spacecraft’s JunoCam imager.

JunoCam’s raw images are available at www.missionjuno.swri.edu/junocam for the public to peruse and process into image products.

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

Hubble Makes a Lucky Observation

What good luck, beautiful image! Click the image for a larger version. The “lucky part” is explained below.

The original caption:

The little-known nebula IRAS 05437+2502 billows out among the bright stars and dark dust clouds that surround it in this striking image from the Hubble Space Telescope. It is located in the constellation of Taurus (the Bull), close to the central plane of our Milky Way galaxy. Unlike many of Hubble’s targets, this object has not been studied in detail and its exact nature is unclear. At first glance it appears to be a small, rather isolated region of star formation, and one might assume that the effects of fierce ultraviolet radiation from bright, young stars probably were the cause of the eye-catching shapes of the gas. However, the bright, boomerang-shaped feature may tell a more dramatic tale. The interaction of a high-velocity young star with the cloud of gas and dust may have created this unusually sharp-edged, bright arc. Such a reckless star would have been ejected from the distant young cluster where it was born and would travel at 200,000 kilometers per hour (124,000 miles per hour) or more through the nebula.

This faint cloud was originally discovered in 1983 by the Infrared Astronomical Satellite (IRAS), the first space telescope to survey the whole sky in infrared light. IRAS was run by the United States, the Netherlands, and the United Kingdom and found huge numbers of new objects that were invisible from the ground.

This image was taken with the Wide Field Channel of the Advanced Camera for Surveys on Hubble. It was part of a “snapshot” survey. These are observations that are fitted into Hubble’s busy schedule when possible, without any guarantee that the observation will take place — so it was fortunate that the observation was made at all. This picture was created from images taken through yellow and near-infrared filters.

Credit: ESA/Hubble, R. Sahai and NASA
Text Credit: European Space Agency (ESA)

BepiColumbo Update

Another milepost reached in the ESA/JAXA BepiColumbo mission to Mercury.

The two science orbiters (the MMO and MPO) are now connected in their launch configuration and will be loaded with propellants this week.

The image is from the process of connecting the orbiters. If you want to really have a nice detailed look ESA has a high resolution image (353k) that is really worth checking out.

About the orbiters (from ESA):

MMO (Mercury Magnetospheric Orbiter)
MMO’s main science goals are to provide a detailed study of the magnetic environment of Mercury, the interaction of the solar wind with the planet, and the diverse chemical species present in the exosphere – the planet’s extremely tenuous ‘atmosphere’.

MPO (Mercury Planetary Orbiter)
The MPO will focus more on surface processes and composition, and together with MMO, will help piece together the full picture of the interaction of the solar wind on the planet’s environment and surface. Together they will watch how this interaction at the surface feeds back into what is observed in the exosphere and how that varies both in time and location – something that can only be achieved with two spacecraft in such complementary orbits.

The mission is proceeding on a time schedule that will launch on 19 October at 01:45 UT atop an Atlas V rocket from Kourou, French Guiana.

Image credit: ESA/CNES/Arianespace/Optique video du CSG – J. Odang

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.

Space Station Leak Update

To update the pressure link on the International Space Station have a look at this entry on the current status.

I keep hearing this leak is in the station itself however the update says it is in the Soyuz MS-09 attached to the station.  That’s scary!  2 millimeters is small but not that small.