Het ontbrekende heelal

Auke Pieter Colijn, werkzaam aan de UvA en UU (bijzonder hoogleraar) is een experimenteel astrofysicus. Hij test of theorieën kloppen. Hij is een van de 40 onderzoekers van de detector in Gran Sasso (LNGS). Het heelal lijkt heel eeg leeg. De massa van sterren en planeten geeft maar een heel lage dichtheid.

Als je de snelheid van sterren in een sterrenstelsel (middels roodverschuiving) meet, verwacht je een afnemende curve. Sterren dichtbij de kern bewegen sneller dan verder weg bij het centrum. Na metingen blijkt dat niet zo te zijn:

Er lijkt massa te missen.

Het hele heelal is 2 graden Kelvin. Samenstelling heelal nu: donkere materie 72%, atomen 4,6%, donkere materie 23%. Donkere materie zendt geen licht uit. 13,7 miljard jaar geleden: donkere materie 63%, atomen 12%, fotonen 15%, neutrino’s 10%.

Donkere energie heb je nodig om te verklaren om te verklaren dat het heelal steeds sneller uitdijdt. Op een gegeven moment (miljarden jaren later) kun je alleen maar de sterren van de Melkweg ziet. Het licht van andere sterren bereikt ons niet meer.

Alles is opgebouwd uit 3 onderdelen: elektronen, up en down quarks.

Theorieën met mogelijke deeltjes die proberen om donkere materie te verklaren:

Het gewicht van donkere materie op aarde is slechts 300 gram. Donkere materie is niet gelijk verdeeld.
3 manieren om donkere materie te meten: indirect via satellieten, zelf maken via een deeltjesversneller en direct meten.

Detectoren richten zich op 1 van de 3 volgende gevolgen van de botsing tussen donkere materie en atomen: warmte, zendt het licht uit of komen er ionen uit (ionisatie). Alle detectoren zitten zo diep mogelijk. Om zo min mogelijk last te hebben van andere deeltjes. De faciliteiten in Gran Sasso (midden Italië):

Waarom moeilijk om te detecteren: nagenoeg is alles radioactief. Alle onderdelen zijn getest op radioactiviteit. Net begonnen met meten. Meest gevoelige detector op dit moment.


Solar Eclipse 2017

Our trip to the Solar Eclipse on 21 August is planned. We plan to see the solar eclipse in Rexburg, Idaho. Totality will last 2 minutes and 17 seconds in Rexburg and Rexburg has a high chance of clear skies in summer. We’ll keep a close eye on the weather forecast and are able to drive to another place.

More info about the solar eclipse in Rexburg can be found at:





Kennedy Space Center

As a true spacefan a visit to the Kennedy Space Center (KSC) is a must go eventually somewhere in your life. I was able to combine a visit to the KSC with my first half marathon at the Spacecoast Marathon in Cocoa Beach.

I stayed at the La Quinta Inn Cocoa Beach, once owned by the Original Mercury 7 astronauts.


I had all day for my visit. And still I couldn’t see and do everything. Beforehand you have to decide what you absolutely want to see and what sights/parts are a bonus. I was there before the doors were open. The doors open at 9 AM. Before the doors open they play the national anthem. Everybody turned to the American flight and sang along. It gave me goosebumps.

The entrance is already impressive.

On the dark grey wall is a part of the famous speech of president J.F. Kennedy:

For the eyes of the world now look into space, to the moon and to the planets beyond, and we have vowed that we shall not see it governed by a hostile flag of conquest, but by a banner of freedom and peace.

At the entrance is also the old countdown clock. It has been at KSC since the Apollo era. It retired in December 2014.

countdown clock.jpeg

So much to see:


The Astronaut Hall of Fame is integrated in the new exhibition Heroes and Legends. This opened on 11 November 2016. It is impressive. The exhibition focuses on the early space missions.


This is the Gemini 9A capsule (by T. Stafford and E. Cernan in 1966) and an original Mercury space suit.

From this exhibition you walk straight into the US Astronaut Hall of Fame.

The second exhibition was the most famous one, Atlantis. My first space shuttle and also the last one that flew (in 2011). This exhibition is huge.

You can easily see it has flown in space numerous times. Near the exhaust you see the damage that was made during the flight.


You may also find the astrovan of the space shuttle program and the spaceshuttle tires of STS-135, the last space shuttle flight.



On a wall between the Heroes and Legends exhibition and the Atlantis exhibition there is a mural of the ISS with all the flags of the partners. Real international cooperation.


Near the mural there is a mockup of the new Orion capsule. Still being tested and hopefully in 2018 the first manned test. This capsule will be used for future Mars missions.


I didn’t want to miss the Astronaut talk. This time John-David Bartoe was there. Bio: http://www.jsc.nasa.gov/Bios/PS/bartoe.html

His talk, like many other astronaut talks, was very entertaining. He talked about his mission (STS-51F) but also about the ISS and the increasing number of female astronauts (yeah).


Next up was the Journey to Mars exhibition with my favorite rover (Opportunity or Spirit) and its big brother Curiosity.


I love this view: a T-38  behind the Atlantis exhibition. The T-38 is used as a trainer for astronauts and as a chase plane.


After a quick lunch and a visit to the Astronaut Memorial (Space Mirror Memorial) for the fallen astronauts during the American space program I went with a bus tour (the explore tour). Our guide was a young student who knew a lot about the most recent developments. First we went to the lookout point where you could see five launch pads, 39A and 39B, 41, 40 and 37B. Here you can see launch pads 41 and 40.


On launch pad 37B you could see the Delta IV rocket sheduled to launch on 7 December. The Air Force’s WGS 8 communications satellite was put into orbit on that day. Nice to be able to see it.


We also stopped at the lookout point for launchpads 39A and B. There were used for the Apollo and the space shuttle program as you can see below. This is launch pad 39A, which is leased by SpaceX for 20 years. It is modified for future SpaceX launches, the Falcon 9 and the Falcon Heavy rockets. In this photo you can still see the rotating support structure for the Space Shuttle. It will be removed for the SpaceX launches. It looked as if there was still a lot of work which had to be done to modify the launch pad.


This is launch pad 39B. Launch pad 39B has been modified by NASA for future Space Launch System (SLS) launches.


The water tank is a part of the  Sound Suppression Water System (SSWS) which was added to protect the Space Shuttle and its payload from effects of the intense sound wave pressure generated by its engines.


This mobile launcher has been modified with this launch tower.The launcher is designed to support the assembly, testing, check out and servicing of the rocket, as well as transfer it to the pad and provide the platform from which it will launch (from the NASA website). It’s much easier to launch from every launch pad this way so saving costs.


This is a crawler used to transport the space shuttles from the VAB to the launch pad. The maximum speed was 1.6 km/hour (1 mph) so taking a couple of hours (average 5) to reach the launch pad )total distance was 5.6 km).


This is the Vehicle Assembly Building or VAB. It’s huge. The space shuttle fitted easily in this building. Now it’s modified for the new SLS.


This is the space shuttle gantry. Sadly it was badly damaged during hurricane Matthew in October 2016.


We were dropped at the Apollo/Saturn V Center. First you enter the firing room and you see the Apollo 8 launch. The first thing you see as you enter the huge exhibition hall is the Saturn V rocket used to go to the moon. It’s huge and very impressive. They have done a great job. The rocket’s first stage is a test stage and the second and third stages are from SA-514, which would have been used for the cancelled Apollo 19 mission.



This is the astrovan of the Apollo program.


This is the official mascot of the Apollo program, Snoopy.


This is the spacesuit of Alan Shepard covered in moon dust!


Apllo 14 Crew module showing the fierce reentry in Earth’s atmosphere.


Practical and other info:

  1. One day is not enough to see and do everything.
  2. Kennedy Space Center is easiest reachable by car. It took me only 20 minutes to get there from Cocoa Beach. You need to pay for parking ($ 10).
  3. The Explore Tour was worth the extra money. More info (from a guide) and 3 stops where you have enough time to look around.




Very Large Telescope (VLT)

Once upon a time …. the members of the European Southern Observatory (ESO) decided to build a Very Large Telescope in Chile. It’sthe start of a great story.

There are 4 telescopes (Antu, Kueyen, Melipal and Yepun) who work together imaging astronomic phenomenons 25 times better than with the individual telescopes. They’re huge. The mirrors have a diameter of 8.2 m!!! The telescopes are situated in Chile,  high in the mountains, with the clearest skies on our planet.

A lot of research is already done with the VLT. You may find more information on the ESO website, which contains a couple of very useful links (especially about the science with the telescopes). http://www.eso.org/public/teles-instr/vlt/

Tours are available under certain conditions: http://www.eso.org/public/about-eso/visitors/paranal/

Now I leave you with some of the most beautiful pictures of the VLT (credit ESO website)




Epic Social Media Gathering at the VLT and ALMA in Chile

ann16010aThe European Southern Observatory organizes a social gathering for 8 lucky people to witness the Mercury transit from Chile. The places were it is held is like a dream. In the middle of the desert with the clearest skies on this planet. A real bucket list place and event for astronomy fans.

Of course I applied. Would be a dream come true for this would be astronomer.

Time to tell something more about my dream of becoming an astronomer. My first presentation at primary school was about the solar system. I must have been 9 or 10 years old and already knew that I wanted to be an astronomer. The planets and stars were fascinating and so much to learn about them. And so much new discoveries in our lifetime. I held onto that dream until I was 18 and had to choose which university I would attend. I graduated high school with a beta orientation (math, physics, chemistry and biology). And then I started to doubt if I was good enough for this program. I was at that moment really unsure of my capabilities and skills (like any other teenagers) and ended up choosing safe. I studied business economics instead. After all this years I’m still sad that I made the wrong choice. But I try to compensate by studying astronomy in my free time.

Going to Chile would be the highlight of my astronomy dream. So pick me!!!

Here you can find more info of this social gathering and you can apply yourself.



Einstein was right: gravitational waves detected

2.5 years ago I already wrote about gravitational waves and the role of the LIGO and the Virgo detectors. On the first day that the two LIGO detectors started a gravitational wave from the merger of two black holes was detected. That’s how it got its name btw: GW150914 (Gravitational Wave 14 September 2015). 

Both black holes weighed 30 times the mass of the sun. The distance to Earth was a mere 1.3 billion light-years. Enormous amounts of energy were released when they merged. This energy changed the fabric of space and time and caused ripples. 

The two LIGO detectors spotted the wave at the same time confirming it was a real discovery. Whole new research lines will appear. Such a triumph for science, the theory of relativity and astronomy.  

Here the figure from the paper: 


TedXESA: Science beyond fiction

I love attending TEDx events. It’s all about Ideas Worth Spreading. After a TEDx event you return full of stories, ideas, inspiration and energy. In the Netherlands almost every city has its own TEDx event.

So when TEDxESA was announced I had to be there. Fortunately I was selected as one of the 300 people. It was held at ESA’s technologic heart ESTEC in Noordwijk (NL). One of my favorite places. A perfect place for a TEDx event.

The list with speakers was also amazing. Astronauts, an Apollo engineer, a cook, writer, entrepeneur were among them. The complete list is here: http://tedx.esa.int/speakers-2015

My definite highlight was Scott Millican. An engineer who worked on several Apollo missions in the late 60’s and early 70’s. He also trained the astronauts. In the break he talked to a small crowd and showed us the original Apollo 12 checklist with notes scribbled on them. He helped putting men on the moon.

Opening by Dutch astronaut André Kuipers:


Danish chef cook Thorsten Schmidt. He cooked an excellent meal for Danish astronaut Andreas Mogensen who stayed at the ISS in September. The Space Rock with a nice surprise inside was delicious.

With Apollo Engineer Scott Millican:


Italian astronaut Samantha Cristoforetti talking about her 200-day stay at the ISS:



You can watch all talks at: http://tedx.esa.int/videos


The next TEDxESA will take place at another favorite place, the European Astronaut Center in Cologne somewhere in 2016. Follow TEDxESA on Twitter or Facebook for updates on this event.