1Do you know why apples turn brown when they've been cut?  Or why bananas get brown spots?  The answer is the same for both fruits: enzymatic browning triggered by an enzyme called polyphenal oxidase (PPO).  Try this simple activity to explore this phenomenon!

What you'll need:
Banana (yellow with no brown spots
Stove
Pot
Water
Timer
Apple
Cutting Board
Knife
Lemon Juice
Distilled Vinegar
Milk

Instructions
Part one
1. Fill a pot with water.
2. With the help of an adult, heat the water to boiling on the stove.
3. Take your banana and look closely at its peel.  Record observations about its color.
4. Carefully submerge the bottom third of the banana in the boiling water for 30 seconds.
5. Remove the banana from the water and observe it for three minutes.  Does the banana look different after awhile? Record your observations.
6. When the banana has cooled down, peel the banana and look at the fruit inside the peel.  Does it look like how you expected it to look?

What happened?
The boiling water caused heat stress on the cells of the banana.  As the cells broke open, they released PPO, which reacted with the air and created melanin.  Most likely, only the peel was affected by the hot water, because the fruit was protected by the peel.  Try more.  What happens if you put a banana in the fridge?  What if you tape up parts of the banana before changing its temperature?

Instructions
Part two
1. Cut two slices from the apple on the cutting board.  Place each slice on its side.
2. Poke one of the apple slices several times with a fork.  Observe both slices for 15 to 20 minutes.  Is there a difference between the two slices?  Do you know why?  Record your observations.
3. Cut five more slices from the apple, placing each slice on its side.  Immediately after slicing, sprinkle milk on the first slice, distilled vinegar on the second slice, lemon juice on the third slice, water on the fourth slice, and leave the fifth slice as is.  Make sure you keep track of which slice is which.  Poke each apple slice several times with a fork.
4. Observe all five slices for 15-20 minutes.  What did each liquid do to the apple slices?  Do you know why?  Record your observations.

What happened?
Slicing the apple damaged its cells due to mechanical stress. This triggers enzymatic browning, just like with the banana.  When you poked the apple, you released more PPO, so that slice was likely much browner than the other slice.  When you sprinkled the slices with liquids, you likely observed that the slices sprinkled with acidic liquids like lemon juice got less brown.  PPO oxidase doesn't work well in acidic environments.  Next time you're eating apple slices and don't want them to turn brown, try a little lemon juice!

Try these easy fruit experiments and let us know how it goes!

As the weather starts to get cooler, here's something neat you can try at home to monitor the changes.  Make your own thermometer!

Supplies:
Empty glass soda bottle
Measuring cup
1/2 cup of water
1/2 cup of rubbing alcohol (with adult supervision)
Food coloring
Clear straw
Modeling clay
Permanent marker

How to do it:
1. Pour the water into the glass bottle.
2. Pour the rubbing alcohol into the bottle.
3. Add a few drops of food coloring and gently swirl the bottle to mix the liquid.
4. Insert the straw into the bottle.  The bottom of the straw should be in the colored water, but not touching the bottom of the bottle.
5. Secure the straw at the top of the bottle with modeling clay.  Do not cover the top of the straw.
6. Place your thermometer in the sun and wait a little while.  The liquid will rise up the straw.
7. Use the marker to to draw a line on the outside of the bottle to show where the top of the liquid is in the straw.  Write the date next to the line.
8. Use your thermometer in the same spot and at the same time each day for a week.  Each time, mark the level of the liquid and the date.
9.  You have collected data!  What does the data tell you about the temperature over the week?

Did you know that farming is all about STEM?  Ever since people started cultivating crops, they have been experimenting with different and better ways to grow food!  Farmers nowadays are on the cutting edge of technology and use critical thinking and problem solving skills all the time.  As the demand for food increases from an ever growing world population, and as we start thinking about feeding people in harsher environments beyond our own planet, innovative STEM projects may hold the answers.  Here are some of the newest innovations being implemented in farming.

Indoor Vertical Farming
Indoor vertical farming is basically exactly what it sounds like.  It's a method of growing crops in stacked layers indoors.  This method is often associated with urban farming where space is limited.  Vertical farming utilizes artificial growing systems like hydroponics and aquaponics.  Vertical farms use up to 70% less water than traditional farms, and can produce more food in less space than traditional farming methods.

Farm Automation
Drones, autonomous tractors, robotic harvesters, and automatic watering are all becoming more and more common on farms.  As robotics technology improves, more and more possibilities become available in agriculture.  Automation on farms is showing promise for reducing the effect of farming on climate change.

Livestock Farming Technology
A wide variety of technology can help improve the management of livestock.  This includes things like Precision Livestock Farming (a collection of technologies that monitor livestock using sensors, cameras, and microphones), and infrared spectroscopy (used to analyze milk for components like fat, protein, and lactose).

Blockchain and Food Traceability
Blockchain technology is making it increasingly possible to solve urgent food safety issues quickly.  Blockchain helps with safety recalls, supply chain inefficiency, and food traceability.  Food traceability has been a time-consuming task, since there are some aspects of food transportation that are still managed on paper.  A blockchain structure streamlines the process and adds accountability to the system.

Now we want to hear your ideas!  What great ideas do you have that could help farmers?  Comment with your thoughts, or try them out at home and let us know how it goes!

The James Webb Telescope is the biggest telescope in space!  It was sent into space to study old and far away things in space.  It is equipped with high-resolution and high-sensitivity instruments to help it in its mission.  It is helping scientists to study new stars, galaxies, and atmospheres of exoplanets.  It is in a solar orbit approximately 930,000 miles from us.  Click through the slideshow to see some amazing images that the telescope has sent back to Earth!  (All image credit goes to NASA.)

There are two distinct subspecies of white rhino.  The southern white rhino is a common and widespread kind of rhino, while the northern white rhino is on the verge of extinction.  Northern white rhinos are listed as critically endangered.  As far as we can tell, they may already be extinct in the wild.  The last male northern white rhino in captivity died in 2018, and the two remaining females have been unable to carry a calf to term.

However, scientists this year announced that they may have discovered a way to save the northern white rhino from complete extinction.  By harvesting eggs from  the female northern white rhinos and using sperm from the dead male northern white rhinos, scientists were able to create viable embryos.  These embryos were implanted into southern white rhinos via IVF.  The procedure produced a successful pregnancy!

Rhinos have long gestation periods--16-18 months!  Sadly, the surrogate mother carrying the northern white rhino fetus died of a bacterial infection eleven months into her pregnancy.  A post-mortem on the surrogate mother found that the embryo had been developing well and had a 95% chance of being born alive if the mother had survived.  Scientists plan to implant more embryos in the coming months and continue trying to save the northern white rhinos.