Lake Dellen - an astrobleme

An impact structure, or astrobleme (meaning "star wound") is a generally circular or craterlike geologic structure of deformed bedrock or sediment produced by impact on a planetary surface, whatever the stage of erosion of the structure. 

The vaguely circular Lake Dellen water system, in Sweden, was formed by an impact crater 89 million years ago (some will even say 100+ M ya), placing the impact in the Late Cretaceous, when the area was hit by a meteorite. 

The initial resulting impact crater measured about 19 kilometers in diameter. Nowadays it's only half that size. The impact resulted in the area containing the rock Dellenite (a rock intermediate in composition between Rhyolite and Dacite), which has become the provincial rock.

In contrast to an impact structure, an impact crater is the surface expression of an impact structure. In many cases, on Earth, the impact crater has been destroyed by erosion, leaving only the deformed rock or sediment of the impact structure behind. This is the fate of almost all old impact craters on Earth, unlike the ancient pristine craters preserved on the Moon and other geologically inactive rocky bodies with old surfaces in the Solar System. 

Asteroid 7704 Dellen was named after it.

An installation of the Sweden Solar System representing Pluto and Charon lies near the southern lake; the pillars holding the model objects are made of dellenite.

Check out the links for more info.

Sources: Magasin Hälsingland (summer issue 2022) and Wikipedia.


Why interested in astronomy

This is an article (or a note, to be more precise) called "Note to self (and others): Why I'm interested in astronomy." that I wrote on Facebook, back in November 2010.
Read, contemplate and enjoy!
/Christofer Döss

Some 80 years ago we started to broadcast TV signals. Every TV signal, every program, every TV show and every film that has been broadcasted through air since then has been transmitted not only to our TV devices but straight out into space as well - as one can hear in the "Contact" movie clip, at http://www.facebook.com/video/video.php?v=466063228672.
The speed of light is almost 300,000 km/second and the distance light makes on a single year is called a light-year.
As electric signals, as well as TV signals, are transfered on wire, in air and in space at a speed close to the speed of light, TV signals has been wooshing thru space for 80 light-years. Follow?
Now we come to the interesting part! 
Our nearest star is of course our own sun. The next nearest star is the "well known" star called Alpha Centauri. That star is only 4 light-years away...! Not even the 50th(!) closest star is close to our first broadcasted TV signals! That star, called DEN 0255-4700, is only 16 light-years away! 
That put one's thoughts in some perspective huh! 
And people are wondering why I'm interested in astronomy...! 

Addendum 1:
The estimated age of the universe is 13.75 ± 0.17 billion years, since the time of the Big Bang. That is: The light from that early Big Bang has been traveling for 13.75 billion years...
In other words: Universe is 13.75 billion light years across!


Addendum 2:
Another aspect of distances is this:
- The light from our moon takes 1 second to reach us on earth
- The sunlight needs 8 minutes to enlight our lives
- The radio signals from the NASA space probe New Horizon, on its way to the dwarf planet Pluto and beyond (estimated flyby of the Pluto system on 14 July 2015), needs 4 hours to reach earth. 
- The Voyager spacecrafts 2 and 1 (launched by NASA in 1977) needs some 15 and 18 hours "of light travel time" to reach earth.  The signals from the Voyager spacecrafts that is.



Earth from Moon and vice versa

These two photos shows Earth as seen from orbit of our Moon - and Moon as seen from orbit of Earth.


My three (now 4) solar eclipses

In the shadow of the upcoming Great American Solar Eclipse, I here recall my three encounters with the moon, blocking our sun.

1.)  My first solar eclipse was back back in the summer of 1990, June 22 to be more exact, in my early 20's, when I travelled with my father from Sweden almost to the Russian border in Joenssuu, Finland, to watch a total. 

We traveled nonstop for 14 hours, both by boat and by car, and got there just in time to experience the deep twilight during the totality, at 04:52 in the morning and midnight sun. We manage to catch a glimpse of it just as the sun took a peak through the clouds. The birds stopped singing and the crowd that had gathered at a football field stopped talking. Even the wind stopped! It was dead calm and no one said a word until the real totality began and a loud "Wow!" could be heard among us sun gazers. Neither of us two had any solar eclipse glasses or shades with us so we couldn't watch directly at the sun, but the mere experience itself was really worth the long journey!

The shadow, white band on the enclosed map, was 240 km wide as it crossed Finland's south-eastern parts.

2.) My second eclipse was a partial, some fifteen years ago or so, when I was at work. Unfortunately I didn't have proper eclipse glasses with me so I didn't see much. On the other side  it wasn't much to see either as not much of the sun was blocked from our part of the world. So if you didn't know what was going on you couldn't tell what was happening, as it didn't get any darker at all.

3.) My third and most recent eclipse was also a partial (but this time a much greater part), just a few years ago here in Sweden, when I was fortunate to be able to watch it from work too, now with proper solar eclipse shades this time.

As this occurred during work hours I didn't have time to prepare any photo equipments so I couldn't take any pictures of it. Luckily this was a sunny day too and the sun had just started to shine through one of the work windows and I could see the moon cover a large bit of the sun, at maximum. The sun looked just like a crescent moon, but much much brighter. That was a pretty cool experience too!

Read more about the August 21, 2017, Great American Eclipse here: 

If you have twitter you can follow my space news account @spaceflashnews there.

Happy solar eclipse viewing!
/Christofer Döss, Sweden

4.) Today's Partial Solar Eclipse, 2018-08-11, over Sweden (up to the North Pole), is my 4th Solar Eclipse - and my 1st that I have managed to get shots of!

As with my second one this Eclipse was also just covered by only a small part of the moon, from our part of Sweden, so you couldn't tell what was happening if you didn't know what was actually going on.

PS 2
A Twitter comment I made about this, illustrated with one of these photos, rendered in a post in an August 12 Space.com article (<--- click="" link="" p="" there="">

"...A little farther north in Sweden, photographer Christofer Döss of Spaceflash News tweeted one of his photos of the eclipse at Petricca. 'The moon took a little bit bigger bite out of the sun up here in Sweden' Spaceflash News tweeted. In northern Sweden, where he captured the photo, the moon was covering about 15 percent of the sun's disk." 


NASA 2014: A Year in Photos!

"Happy New Year 2015!

Thank You Google+ Fans!

Google+ Photos:

#NASA #Space #HappyNewYear #Astronomy #ISS #Astronauts #Science #Technology #Engineering #STEM #Exploration #ESA #CSA #JAXA #Roscosmos #Photos #YearInPhotos

/ Friends of NASA, 31 dec. 2014"