1) The Hubble Space Telescope, launched in 1990, has provided breathtaking images of distant galaxies and deep space.

2) The impact of social media platforms on society and politics has been a subject of debate, including concerns about misinformation, privacy, online harassment, and the influence of these platforms on public opinion and democratic processes.

3) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.

4) The taco, originating from Mexico, is a versatile and flavorful dish enjoyed worldwide. It consists of a tortilla filled with various ingredients, such as seasoned meat, vegetables, cheese, and salsa. Tacos can be made with soft corn tortillas or crispy shells and can be customized with different toppings and fillings. They are a popular street food, casual meal option, and a symbol of Mexican culinary heritage and vibrant flavors.