Galactic habitable zone

Solar systems that can support life as we know it, we’ve learned, are not likely to be anywhere in a galaxy. Scientists, in 2021 believe some things …

  • The Milky Way Galaxy is a disk, with a greater density of stars and solar systems in the center
  • The Milky Way Galaxy is a bar spiral, in that it has two or four arms and a center mass
  • The Milky Way is around 100 million light years across
  • Stars at the outer edge of the arms are accompanied by fewer heavy atoms, like iron and carbon
  • Stars nearer the center of the galaxy are in a domain of high levels of radiation compared to the Sun

In our hippie past, we marveled at the Drake Equation, an attempt to illustrate the likelihood of life on another planet.

Asteroid 2000 QW7

Watch an Asteroid Fly by Earth Today in a Live Webcast from … › asteroid-flyby-september-2019-slooh-webcast

An asteroid known as 2000 QW7 is expected to pass by Earth closely, but safely, at 3.3 million miles (5.3 million kilometers) from Earth

NASA: Two asteroids will fly safely by Earth this week, so just … › news › nasa-two-asteroids-will-fly-safely-by-earth-…

NASA used this image of the far-off Vesta asteroid to illustrate its release on this week’s asteroids. NASA.

NASA news: NASA orbit video shows monster asteroid set to … › News › Science

The Asteroid, called 2000 QW7, was first discovered by NASA on August 8, 2000.

Large Asteroid 2000 QW7 to pass Earth – Comet Watch › large-asteroid-2000-qw7-to-pass-earth

On Saturday 14 September, 2019 a large asteroid (designated asteroid 467317 2000 QW7) will pass the Earth

Mars Mission 2020

Nasa will launch a mission to Mars in 2020. This may sound shocking until you learn that this will be another unmanned mission sending a robotic rover to explore the surface and perform experiments.

Manned Mission

The next manned mission to another terrestrial object will probably be a 2024 mission to the moon. We should be good at this, and it is good practice for manned exploration of other terrestrial destinations.

How soon?

The soonest time we might imagine a manned mission to Mars, even just for orbit, would be 2033 returning in 2035. The departure and return times would normally be about 26 months apart. Based on the orbit of the Earth and Mars, 26 months pass between minimums when travel time and energy required would be ideal. Travelling at the wrong time could increase the time and energy required by double. Ideal travel windows for the shortest possible mission (26 months) occur twice a century.

Consider that picking the ideal time would allow the mission to leave Earth and travel to Mars and return in just over 26 months. Picking the worst time for the mission could require in excess of five to ten years to complete.


A variable of great import in a trip to Mars is the type and quantity of fuel to use. To achieve the fastest travel time, you would want to accelerate until half way to Mars, and then decelerate until you land. You would need of course, to have plenty of fuel left to get home.

Asteroid 2019 OK

On July 24, 2019 an asteroid measuring between 60 and 140 meters in diameter whizzed by planet earth. It was the largest bolide to come between the Earth and the Moon this year. To compare, the Chelyabinsk meteor was estimated to be around 20 meters in size, where 1,491 injuries were reported according to Wikipedia.

Surprise asteroid whizzed by Earth today, and we didn’t even blink via @CNET

An asteroid just buzzed past Earth, and we barely noticed in time via @ConversationEDU

Asteroid 2019 OK to flyby Earth at 0.19 LD on July 25 – the largest of the year

Fritz Zwicky

Born around 1900, just 10 years or so younger than Albert Einstein was a truly remarkable astronomer. The father of Dark Energy, Fritz Zwicky was the son of a Swiss Industrialist who lived in Bulgaria.

Dark Matter

Fermi-Lab scientists have spent the last 15 years or so searching for particles of Dark Matter. Using a disk of Gallium metal cooled to nearing zero Kelvin, scientists have not detected the particles. They sought out a particle with mass, traveling at less than the speed of light and unimpeded by other matter.

Missing Matter

Fritz Zwicky first referred to Missing Matter or Missing Mass when he observed galaxies at Mount Wilson, and calculated their mass and the speed of rotation. He found that stars near the edge of the galaxy sped around its center too quickly. Based on the gravitational pull of the galaxy, they should have been flung into space.


It was refreshing to see Bezos show off his lunar module, Blue Moon and its capabilities. Travel to our Moon can take less than a week, and offers a staging ground with an escape velocity substantially lower than Earth’s.

The Moon has a surface area larger than the entire continent of Africa. The State of Texas is 150 times smaller in surface area than the Moon. With a very thin atmosphere, high speed trains could travel the Moon at 1,000 km/hr, or higher.

Musk has touted the importance of Martian habitation. It’s fine that he works on that, while Musk and Bezos each grab roughly $5 billion in federal subsidies per annum they have produced greater results then would have been achieved by a NASA program for a higher cost.

Economists estimate that in 2019 dollars, the Apollo Program cost NASA $ 119 billion. Estimates of the per shot cost for Space Shuttle program put the cost at around $ 500 million per mission.

Lacking a launch program, the Air Force and NASA have used a combination of Amazon and Tesla launch programs, the United Launch Alliance, consisting of Boeing and Lockheed and even Russian government launch programs.

The European Space Agency also uses the Ariane program with launch costs around $150 million per mission.