Category Archives: Nature

Behold: a meteor, but an especially bright one (even brighter in reality than seen here), and therefore entitled to a more vivid descriptor. To wit:

The International Astronomical Union defines a fireball as a meteor brighter than apparent magnitude -4, which corresponds (roughly) to being brighter than any planet — as well as bright enough to cast a human-noticeable shadow. Pictured, an astrophotographer taking a long-duration sky image captured by accident the brightest meteor he had ever seen. Clearly a fireball, the disintegrating space-rock created a trail so bright it turned night into day for about two seconds earlier this month. The fireball has been artificially dimmed in the featured image to bring up foreground Lake Louise in Alberta, Canada. Although fireballs are rare, many people have been lucky enough to see them. If you see a fireball, you can report it. If more than one person recorded an image, the fireball might be traceable back to the Solar System body from which it was ejected.

(Image: Hao Qin)


Behold: Mammatus clouds – the most stacked of all suspended aerosols. To wit:

Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms. Under some conditions, however, cloud pockets can develop that contain large droplets of water or ice that fall into clear air as they evaporate. Such pockets may occur in turbulent air near a thunderstorm. Resulting mammatus clouds can appear especially dramatic if sunlit from the side. The mammatus clouds pictured here, lasting only a few minutes, were photographed over Regina, Saskatchewan, Canada, just after a storm in 2012.

(Image: Michael F Johnston)


How best to watch a meteor shower? Well, later this week, the annual Perseid Meteor Shower will hit its peak. So what next for the avid skywatcher? To wit:

One thing that is helpful is a dark sky, as demonstrated in the featured composite image of last year’s Perseids. Many more faint meteors are visible on the left image, taken through a very dark sky in Slovakia, than on the right image, taken through a moderately dark sky in the Czech Republic. The band of the Milky Way Galaxy bridges the two coordinated images, while the meteor shower radiant in the constellation of Perseus is clearly visible on the left. In sum, many faint meteors are lost through a bright sky. Light pollution is shrinking areas across our Earth with dark skies, although inexpensive ways to combat this might be implemented.

(Image: Tomas Slovinsky (Slovakia) & Petr Horalek (Czech Republic; Institute of Physics in Opava)


A stunning macro image of sand from a Mallorca beach by Cologne-based photographer Ole Bielfeldt – a colourful composition of minute but highly detailed fragments of coral, quartz and shells of which Bielfeldt sez:

Although to the naked eye this looks like very clean natural sand, pieces of micro-plastic, as seen in the last image, can be found when viewed under the microscope.

More of his tiny universes here and here.


Evocative aerial shots of the pink waters of the Camargue river delta near Arles in southern France by Paolo Pettigiani, of which he sez:

The pink water comes from a pink algae (Dunaliella Salina) which lives in it. This pink algae can exist in just about any kind of natural body of saltwater and is the main source of nutrition for another common resident of saltwater: a miniscule shrimp called the artémias salina.