Phoenix was an unmanned space probe that landed on Mars on May 25, 2008 and operated until November 2, 2008. It was released on August 4, 2007. Phoenix operated on Mars for 157 sols (161 days). Its instruments were used to assess the local habitability of Mars and to investigate the history of water on the planet. The mission was part of the Mars Scout Program, and its total cost, including launch costs, was $420 million.

On August 4, 1958, Billboard debuted the Hot 100, an all-genre singles chart. The Hot 100 quickly became the industry standard, and on October 13, 1958, Billboard discontinued the Best Sellers In Stores chart.

American Meghan, Duchess of Sussex (born August 4, 1981), a former actress, is a member of the British royal family. Markle grew up in Los Angeles, California, where she was born. At Northwestern University, she began her acting career; her final and most notable on-screen performance was as Rachel Zane for seven seasons (2011–2018) in the American TV legal drama Suits.

Louis Daniel Armstrong (August 4, 1901 – July 6, 1971) was an American trumpeter and vocalist known as "Satchmo," "Satch," and "Pops." He is one of jazz's most influential figures. His career spanned five decades and several eras in jazz history. Armstrong was born in New Orleans and raised there. Armstrong, who rose to prominence in the 1920s as an inventive trumpet and cornet player, was a foundational influence in jazz, shifting the emphasis of the music away from collective improvisation and toward solo performance. Around 1922, he moved to Chicago to join his mentor, Joe "King" Oliver's, Creole Jazz Band.

APSARA was the first research reactor in Asia to reach criticality when it did so on August 4, 1956. It was a pool-type reactor with a 1 MW output that used 4.5 kg of highly enriched uranium in the form of plates as fuel. Both the moderator and the coolant were made of light water.

Mohandas Karamchand Gandhi's youngest and fourth son, Devdas Mohandas Gandhi, was born on May 22, 1900, and died on August 3, 1957. He was raised in the Natal Colony and moved to India with his parents when he was an adult. He got involved in his father's movement and served several jail terms for it. He rose to prominence as a journalist as well, holding the editor position at Hindustan Times.

Gopal Sharma, who was born on August 3, 1960, played cricket for India in 5 tests and 11 one-day internationals between 1985 and 1990. Although he was an off-spinner, Laxman Sivaramakrishnan, Maninder Singh, Arshad Ayub, Shivlal Yadav, Ravi Shastri, and Narendra Hirwani eclipsed him for a spot in the international team.

Barack Hussein Obama, an American politician born on August 4, 1961, led the country as its 44th president from 2009 to 2017. He served as the country's first African-American president. He was a Democrat and previously held the offices of Illinois state senator from 1997 to 2004 and U.S. senator from Illinois from 2005 to 2008.

American filmmaker, actor, comedian, author, YouTuber, podcaster, and comic book writer Kevin Patrick Smith was born on August 2, 1970. He first gained notoriety with the low-budget buddy comedy Clerks (1994), which he wrote, directed, co-produced, and starred in as the stoner duo Jay and Silent Bob's Silent Bob. These characters also appeared in Smith's later films Mallrats (1995), Chasing Amy (1997), Dogma (1999), and Jay and Silent Bob Strike Back (2001)

Indian playback singer and actor Kishore Kumar was born on 4 August 1929 and passed away on 13 October 1987. He is regarded as one of the greatest and most versatile singers in Indian music history. He was one of the most well-known singers in the Indian film industry and was well-known for his yodelling and versatility.

Arbaaz Khan is an Indian actor, director, and producer best known for his work in Hindi-language movies. He was born on August 4, 1967. In addition, he has appeared in a few television shows and films in the Urdu, Telugu, and Malayalam languages.

Indian film director, screenwriter, producer, music composer, and playback singer Vishal Bhardwaj was born on August 4, 1965. He has won seven National Film Awards in four categories and is well known for his work in Hindi film.

Santa Claus Land debuted on August 3, 1946, as the world's first themed amusement park. On the first day, visitors would not find roller coasters. Instead, there was a miniature circus, a restaurant, and, of course, Santa Claus!

Sunil Chhetri, a forward for Bengaluru of the Indian Super League and the India national team, was born on August 3, 1984. Chhetri, who is regarded as one of the greatest Indian players of all time, is the player with the most caps for India and the top goalscorer of all time. He is also tied for the fifth-highest international goalscorer of all time with Cristiano Ronaldo and Lionel Messi.

Martha Helen Stewart (born August 3, 1941) is a retail businesswoman, writer, and television personality from the United States. She achieved success as the founder of Martha Stewart Living Omnimedia through a variety of business ventures, including publishing, broadcasting, merchandising, and e-commerce. She is the publisher of Martha Stewart Living magazine and the host of two syndicated television shows: Martha Stewart Living, which aired from 1993 to 2004, and Martha, which aired from 2005 to 2012.

Maniesh Paul, an Indian television presenter, anchor, model, singer, actor, and comedian in Bollywood, was born on August 3, 1981. He began his professional career as an RJ and VJ before transitioning to acting, stand-up comedy, and hosting.