August 25 – Entering Interstellar Space....

Posted on August 25, 2019

There is no boundary line in space. 

There's no "Welcome to Interstellar Space" sign.

If you tried to define "interstellar space" as the space between stars, then ALL of space, other than those portions taken up by stars, would be counted as interstellar space. Like even the bit of space you are sitting or standing or lying down on.

That's not how we use the term. 

No, scientists define interstellar space as the place where the Sun's constant flow of ions - something called the solar wind - AND the Sun's magnetic field both stop affecting the surroundings. And even though that defined boundary is invisible to our eyes, it has a special name: the heliopause. 

(You probably know that helio- means Sun.)

Since the Sun is a sphere, and it emits ions in every direction, we call the sphere in which the solar wind and the Sun's magnetic field affects space the heliosphere.

If you were ever to reach interstellar space in a well-equipped spaceship, you would find that there you could detect many more particles around you, more than inside the heliosphere - but you'd also discover that the particles were very much colder. You'd be able to detect magnetic fields that don't originate from the Sun, and interstellar winds rather than the solar wind!

On this date in 2012, Voyager 1 became the first human-made object to enter interstellar space! (It took it almost 35 years to get there!)

I knew that the farthest reaches of the solar system, way beyond the heliopause, is the spherical "shell" of icy bodies called the Oort Cloud. 

Notice that this is not an ordinary to-scale diagram;
it's an exponential scale.

Check out how long it will take Voyager 1 to get to, and then to get through, the Oort Cloud:

• Voyager 1 will reach the beginning of the Oort Cloud around 300 years from now.

• And it will reach the end of the Oort cloud in 30,000 years!!!

• And in 40,000 years, the spacecraft will finally be closer to another star than to our Sun!

Wow. 

Mind blown!

Also on this date:

Anniversary of the beginning of the Belgian Revolution

Anniversary of the liberation of Paris

Anniversary of the Great Moon Hoax

Composer Leonard Bernstein's birthday

Constitution Day in Paraguay

Free Entrance Days at National Parks

National Second-hand Wardrobe Day

Dia de Soldado in Brazil

Independence Day in Uruguay

Plan ahead:

Check out my Pinterest boards for:

• August holidays
• August birthdays
• Historical anniversaries in August

And here are my Pinterest boards for:

• September holidays
• September birthdays
• Historical anniversaries in September
  
  

December 23 – Flight Firsts

Posted on December 23, 2013

I'm busy wrapping presents and baking cookies, but not everyone throws themselves into Christmas preparations at this time of the year—not even everyone who celebrates Christmas necessarily spends December getting ready! Today is the anniversary of some important “firsts” that have nothing to do with the holidays!

I like the fact that the "8" of
Apollo 8 makes a fairly decent
picture of the flight of the spacecraft!

On this date in 1968, three American astronauts became the first humans to orbit the moon. Frank Borman, Jim Lovell, and William Anders orbited the moon as a part of their Apollo 8 mission—a necessary step before astronauts eventually landed on the moon with Apollo 11.

I wasn't sure whether or not to call
this aircraft an "airplane."
Unusual looking, isn't it?

And...

On this date in 1986, an aircraft called Voyager became the first to fly around the world without stopping and even without refueling. Jeanna Yeager and Dick Rutan had started off from Edwards Air Force Base in California on December 14 and ended 9 days, 3 minutes and 44 seconds later. This flight more than doubled the flight distance record that had been set in 1962.

Okay, back to the gift wrapping station or maybe the kitchen. I'm so not into setting records or doing world's-firsts right now. But maybe you are—or will be, someday!

Also on this date:

 Anniversary of Benjamin Franklin's shocking mistake 

Anniversary of a man crossing the ocean with no food 

Linguist Jean-Francois Champollion's birthday

Night of the Radishes

Festivus—the Holiday for the Rest of Us

Plan ahead:

Check out my Pinterest pages on:

• December holidays 
• December birthdays
• Historical anniversaries in December
  

And here are my Pinterest boards for:

• January holidays 
• January birthdays 
• Historical anniversaries in January

August 20, 2010

Voyager 2 Launched – 1977

This unmanned spacecraft took photos and measurements of Jupiter, Saturn, Uranus, and Neptune and then streaked out of the solar system towards the stars. It carried a 12-inch copper phonograph record with recorded greetings from Earth people in 60 languages, along with samples of music and natural sounds including whale singing. Electronic information that an advanced technological civilization could convert to diagrams and pictures accompanies the music.

Voyager 2 has been in continuous operation for 12,016 days now, and it is more than 14 billion kilometers away from the sun. It takes almost 13 hours for signals from the spaceship to reach Earth.

The data we are now receiving from the spacecraft concerns the properties of the solar wind and its interaction with interstellar winds.

Did you know that there was wind in space? The sun ejects streams of charged particles in all directions, making a sphere or a “bubble” in the interstellar medium (gas and dust) that surrounds the solar system. This bubble is called the heliosphere.

I know you've probably heard that outer space is a vacuum, which means that it is pretty much empty—no matter at all... Now I'm saying that there are charged particles, gas, and dust, let alone all the radio waves, light, and other forms of radiation. But the matter in outer space is so sparse, it still makes a high-quality vacuum that is hard for us here on Earth to copy, with just a few atoms per cubic centimeter.

Check out the Voyager website!

Don't forget to check out the kids' section.