Search found 7 matches

by Simen1
Mon Mar 15, 2021 10:35 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Meteor Fireballs in Light and Sound (2021 Mar 15)
Replies: 14
Views: 5636

Re: APOD: Meteor Fireballs in Light and Sound (2021 Mar 15)

Meteors that go below about 30 km height also makes an infrasound roar at a few Hz. If there are several infrasound microphones within reach, it can be combined with wind data to triangulate the path even during the dark flight period. Infrasound triangulations may be very accurate due to the low sp...
by Simen1
Mon Feb 17, 2020 10:20 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: The Changing Surface of Fading... (2020 Feb 17)
Replies: 27
Views: 10245

Re: APOD: The Changing Surface of Fading... (2020 Feb 17)

Alex: The bluring effect is "optical unsharpness", and not a fuzzy star. We just dont have big enough telescopes to get higher resolution visible light images. Maybe radio telescope interferometry may help. Or just wait for JWST.
by Simen1
Sun May 31, 2015 7:14 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Approaching Pluto (2015 May 27)
Replies: 33
Views: 4252

Re: APOD: Approaching Pluto (2015 May 27)

They probably use lots of techniques. First removing all the known disturbances like internal reflections inside LORRI and compensating for vignetting. Deconvolution are "wrapping" optical distortions backwards via advanced knowledge of how the distortions are made and computer algorithms....
by Simen1
Sat May 30, 2015 9:32 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Approaching Pluto (2015 May 27)
Replies: 33
Views: 4252

Re: APOD: Approaching Pluto (2015 May 27)

The size threshold at which a body becomes round is highly uncertain, perhaps 200-1200 km. Ref http://mel.ess.ucla.edu/jlm/epo/planet/AAS09JLM.pdf p.12 https://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size Pluto is almost 1200 km in diameter and thus at the high end of sizes that might ...
by Simen1
Thu May 28, 2015 12:32 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Approaching Pluto (2015 May 27)
Replies: 33
Views: 4252

Re: APOD: Approaching Pluto (2015 May 27)

I think its a too interesting thought to skip. Let me try four scenarios: 1.1 New Horizon is passing by a California Air Base at 10 000 km distance (same as New Horizons will pass Pluto) at a speed of 13,8 km/s. In comparison ISS is in a low earth orbit currently about 355 km altitude and 7,66 km/s ...
by Simen1
Sun Mar 15, 2015 9:28 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Total Eclipse at the End of the World (2015 Mar 15)
Replies: 7
Views: 2718

Re: APOD: A Total Eclipse at the End of the World (2015 Mar

A total solar eclipse will occur on Friday and be visible from the north Atlantic Ocean.
More important in this context, the total eclipse this friday will be observable from the north pole, as the sun slides along the horizon.
by Simen1
Sat Feb 21, 2015 11:06 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: 45 Days in the Sun (2015 Feb 21)
Replies: 7
Views: 74758

Re: APOD: 45 Days in the Sun (2015 Feb 21)

What does it take to make a digital solargraphy? I don't mean scanning the film or photopaper, but with a digital sensor. It's not as simple as setting the camera to bulb. The scene may be much to contrasty for digital sensors. The sensor will get saturated and the battery will drain. An very dark N...