South Pole Telescope

Knate Myers - View from the ISS at Night

The Great Comet of 1881  -   Étienne Léopold Trouvelot  1881

French 1827-1895

Vintage illustration, Comet over observatory in night time sky

Starry Night Castle. Credit & Copyright: P-M Hedén

The Pleiades star cluster seems to lie just beyond the trees above a dark castle tower in this dramatic view. This starry sky also features bright star Aldebaran below the Pleiades and a small, faint, fuzzy cloud otherwise known as Comet Holmes near picture center at the top of the field. Starry Night Castle might be an appropriate name for the medieval castle ruin in the foreground. But its traditional name is Mörby Castle, found north of Stockholm, near lake Skedviken in Norrtälje, Sweden.

Great Red Spot closeup

via reddit

Sean Goebel - Mauna Kea Heavens 2 | gif by FD

General Ham: Digital Mode Introduction

This is probably a bit more repetition, but well worth the time!  So digital modes are where data are encoded as bits instead of in waves, and some are created commercially, while others are created by amateurs!  

Digital modes consist of two things: a protocol and a method of modulation.  A protocol is the set of rules that control the encoding, packaging, exchanging and decoding of digital data.  For example, packet radio uses the AX.25 protocol standard.  This standard says how each packet is constructed, how packets are exchanged, what characters are allowed, and so forth.  The protocol standard doesn’t say what kind of transmitter to use or what the signal will sound like on the air.

Digital mode signals are restricted to the CW/data segments of each band and most digital mode operation is close to the top of the CW segment.  Calling frequencies for the popular digital modes are incorporated into band plans and are usually the lowest frequency of operation with operators moving up in frequency as activity increases.

For example on 20m, most PSK31 signals are found near 14.070 MHz.  RTTY and other digital mode signals are found above that.  The modems used for digital signals often do not recognize signals from CW or other digital modes.

Here’s the Digital Signal Band Plan:

@atdiy/@tymkrs

What a stunner! See Jupiter’s southern hemisphere in beautiful detail in this new citizen-scientist-processed JunoCam image.

What Happened to Mars?

Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm.

Today, Mars is bitter cold. The Red Planet’s thin and wispy atmosphere provides scant cover for the surface below.

Our MAVEN Mission

The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission is part of our Mars Scout program. This spacecraft launched in November 2013, and is exploring the Red Planet’s upper atmosphere, ionosphere and interactions with the sun and solar wind.

The purpose of the MAVEN mission is to determine the state of the upper atmosphere of Mars, the processes that control it and the overall atmospheric loss that is currently occurring. Specifically, MAVEN is exploring the processes through which the top of the Martian atmosphere can be lost to space. Scientists think that this loss could be important in explaining the changes in the climate of Mars that have occurred over the last four billion years.

New Findings

Today, Nov. 5, we will share new details of key science findings from our ongoing exploration of Mars during a news briefing at 2 p.m. EDT. This event will be broadcast live on NASA Television. Have questions? Use #askNASA during the briefing.

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